tag:blogger.com,1999:blog-71646036496605396192024-03-13T06:34:06.652-04:00Somewhat AbnormalScience, religion, and whatever else is on my mind...Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.comBlogger226125tag:blogger.com,1999:blog-7164603649660539619.post-22710847372103162992015-04-05T10:24:00.000-04:002015-04-05T10:24:35.854-04:00A New ProofI have just discovered a new proof of the existence of God.<br />
<br />
Consider the following sentence:<br />
<br />
(S) If this sentence is true, then God exists.<br />
<br />
Suppose sentence S is true. Then the first clause is satisfied, so the second clause is true. Thus, God exists.<br />
<br />
What the preceding paragraph proves is that <i>if</i> sentence S is true, <i>then</i> God exists. But that is exactly what sentence S asserts. So that means we have proved that sentence S is true! And therefore God really does exist.<br />
<br />
As a result of this proof I am longer an atheist. Sorry to disappoint everyone.*<br />
<br />
<span style="font-size: xx-small;">* Note this proof also works for unicorns. Yay, unicorns exist!</span>Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com1tag:blogger.com,1999:blog-7164603649660539619.post-79872066646441446442014-10-21T10:47:00.002-04:002014-10-27T15:52:55.191-04:00Craig and BGVI hate writing more posts about William Lane Craig, because I think he gets way more attention than he deserves already. But.... I can't let this pass.<br />
<br />
I just ran across <a href="http://www.reasonablefaith.org/sean-carrolls-reply-to-the-rf-podcast" target="_blank">this post</a> from Craig's website. Craig is responding to Carroll and, after quoting him, replies thusly:<br />
<br />
<br />
<blockquote class="tr_bq">
Here
Carroll claims that to have a singularity in the past does not mean to
have a beginning; it means only that SOME [past-directed] geodesics come
to an end. He says that others might not. On this interpretation, the
BGV Theorem is consistent with some geodesics’ being infinitely
extended into the past. But that is precisely what the theorem proves
to be impossible. The theorem requires that ALL actual, past-directed
geodesics eventually come to an end. In order for the universe to be
beginningless, there must be infinite, past-directed geodesics. That’s
why Borde, Guth, and Vilenkin take their theorem to prove that any
universe which has, on average, been in a state of cosmic expansion
throughout its history cannot be past-eternal but must have a beginning.<br />
<div style="background-color: white; border: medium none; color: black; overflow: hidden; text-align: left; text-decoration: none;">
<br /></div>
</blockquote>
OK, so, in my last post (yeah, I know, no apologies, I'm only going to post when I feel like it, so there), I quoted the conclusion from the <a href="http://arxiv.org/abs/gr-qc/0110012" target="_blank">actual BGV paper:</a><br />
<br />
<blockquote class="tr_bq">
... we see that if Hav > 0 along any null or noncomoving<br />
timelike geodesic, then the geodesic is necessarily<br />
past-incomplete. </blockquote>
So, it's obvious from the paper that the requirement that a geodesic ends is <b>not</b> applicable to geodesics that are timelike and comoving. In other words, Craig is simply wrong when he writes that BGV requires "ALL actual, past-directed
geodesics eventually come to an end."<br />
<br />
Either Craig hasn't understood the conclusion of the paper he cites so frequently, or he is deliberately mischaracterizing the paper for his readers so that they will think he has decisively refuted Carroll. <br />
<br />
What do you think?Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com0tag:blogger.com,1999:blog-7164603649660539619.post-24374969648399916652014-05-23T09:02:00.000-04:002014-05-23T09:03:18.424-04:00BGV and KCMOK, so <a href="http://somewhatabnormal.blogspot.com/2014/05/the-universe-is-infinitely-old-says.html" target="_blank">last time</a> I claimed that our best, experimentally successful model of the early universe is one that is infinitely old and has no initial singularity. If you are savvy about these things (from listening to Craig debates, for instance) you are wondering, "But what about the <a href="http://arxiv.org/abs/gr-qc/0110012" target="_blank">Borde-Guth-Vilenkin theorem</a>? Doesn't it prove that an inflating universe must have had an initial singularity?" The answer is, "No, it doesn't."<br />
<br />
There has been a lot of confusion about this, with clip quotes from one or another of the paper's authors being traded to "prove" that the theorem does, or doesn't, prove the universe had a beginning. So let's look at what the theorem actually says. <br />
<br />
"Any theorem is only as good as its assumptions," <a href="http://www.reasonablefaith.org/honesty-transparency-full-disclosure-and-bgv-theorem" target="_blank">writes Alexander Vilenkin</a> in a letter to Lawrence Krauss. So let's start with the assumptions of the theorem. Roughly speaking, there are two:<br />
<ol>
<li>Spacetime is classical.</li>
<li>Spacetime is expanding on average.</li>
</ol>
(I say "roughly speaking" because there are all sorts of technical issues about spacetime congruences and so forth that one needs to make these assumptions precise, but I think these short versions are sufficient to understand the main philosophical issues involved.)<br />
<br />
Now let's jump to the conclusion, which I quote from their paper:<br />
<blockquote class="tr_bq">
... we see that if Hav > 0 along any null or noncomoving<br />
timelike geodesic, then the geodesic is necessarily<br />
past-incomplete. </blockquote>
Some translation: a "timelike geodesic" is simply the path that an object will travel on if it is not subject to any forces other than gravity. Similarly, a "null geodesic" is the path that a light ray will travel. "Hav > 0" is the mathematical statement of assumption (2.): the universe is expanding on average. "Past-incomplete" means that if you try to follow one of these paths backwards in time, you can only do so for a finite amount of time.* <br />
<br />
OK, so here's my first point: <b><i>the BGV theorem is <u>not</u> a singularity theorem!</i></b> <br />
<br />
The conclusion says nothing at all about singularities: it only says that certain paths cannot be extended infinitely backward in time. <i>One way</i> that this might happen is if the path encounters a singularity. But that is not the <i>only</i> way it can happen.<br />
<br />
The other thing that can happen is that, as we trace the path backward in time, we encounter a region where one (or both) of the assumptions of the theorem is no longer valid.<br />
<br />
Start with assumption (2.). The path can enter a region in which spacetime is static, or contracting, or cyclically expanding and contracting. Then assumption (2.) is violated and the theorem's conclusion is avoided. <i><b>In spacetimes like these, the BGV theorem simply doesn't apply.</b></i><br />
<br />
What about assumption (1.)? Classical spacetime is a pretty basic assumption in any sort of cosmology. But it is expected to break down in the quantum gravity regime, where we encounter "spacetime foam" of some sort. This is difficult to discuss, since in the absence of a good theory of quantum gravity, no one has any idea what spacetime foam should look like. But it's possible that the BGV theorem is pointing us to a place where quantum gravity comes into play.<br />
<br />
So the BGV theorem does have something very interesting to tell us about the early universe: namely, that the infinitely old, infinitely expanding inflationary period that I discussed in the previous post <b>cannot</b> be the end of the story. Not just because of vague speculations about the Planck epoch, but because of the properties of classical spacetime itself. Here's what the authors said in the paper itself:<br />
<blockquote class="tr_bq">
Whatever the possibilities for the boundary [where the geodesics come to an end - RNO], it is clear that unless the averaged expansion condition can somehow be avoided for all past-directed geodesics, inflation alone is not sufficient to provide a complete description of the Universe, and some new physics is necessary in order to determine the correct conditions at the boundary. This is the chief result of our paper.</blockquote>
<br />
But the BGV theorem does <b>not</b> say that spacetime must be singular; still less does it say that there was an <i>initial</i> singularity from which the entire universe arose. This is why I say that the theorem is irrelevant to the <a href="http://www.philosophyofreligion.info/theistic-proofs/the-cosmological-argument/the-kalam-cosmological-argument/" target="_blank">Kalam Cosmological Argument</a>: it doesn't say anything about whether the universe had a beginning or not.<br />
<br />
<span style="font-size: x-small;">* A few more technical points: by "backward in time" I mean in the opposite time direction from the direction in which the universe is expanding. And by "finite amount of time" I mean time as measured by a clock carried along with the moving object (proper time). In the case of null (light) rays, we have to use an "affine parameter" rather than the proper time.</span>Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com2tag:blogger.com,1999:blog-7164603649660539619.post-64739242061067369272014-05-22T09:37:00.000-04:002014-05-22T09:37:20.317-04:00The Universe Is Infinitely Old (Says Cosmology)The Secular Student Alliance at my school recently hosted a debate on the topic "Is there a God?" The theist side was very well prepared and did a great job in the debate, as even the secular students in the audience agreed. One of the arguments they presented was the <a href="http://www.philosophyofreligion.info/theistic-proofs/the-cosmological-argument/the-kalam-cosmological-argument/" target="_blank">Kalam Cosmological Argument</a>, which was presented rather the same way that <a href="http://www.reasonablefaith.org/the-existence-of-god-and-the-beginning-of-the-universe" target="_blank">William Lane Craig presents it</a>. The discussion brought up the Borde-Guth-Vilenkin Theorem (BVG for short), which Craig has used as well, as support for the premise "The universe began to exist." I want to talk about why the BVG theorem is irrelevant to the Kalam Cosmological Argument, but first, by way of preliminary, I want to discuss the current state of cosmology.<br />
<br />
Cosmology begins with Einstein's equations of General Relativity (GR for short), and asks whether these equations, applied to the universe as a whole, are capable of explaining what we see when we look out into deep space. GR relates the curvature of spacetime to the energy content in the universe, so in order to solve the equations we need to know what the universe is filled with. There are three basic types of energy we need to consider:<br />
<ul>
<li><b>Matter</b> in the form of galaxies, dust, dark matter, and the like,</li>
<li><b>Radiation</b>, including particles moving so fast that they are relativistic, and</li>
<li><b>Cosmological constant</b>, aka "dark energy."</li>
</ul>
The three forms of energy behave differently, so different ones are important at different times in the evolution of the universe. For most of the last 13.7 billion years, the expansion has been <a href="http://en.wikipedia.org/wiki/Matter-dominated_era" target="_blank">matter-dominated</a>. But in the far future, the expansion will be <a href="http://en.wikipedia.org/wiki/Dark-energy-dominated_era" target="_blank">dominated by the cosmological constant</a>, and at very early times (the first 50,000 years or so), the expansion was <a href="http://en.wikipedia.org/wiki/Radiation-dominated_era" target="_blank">dominated by radiation</a>.<br />
<br />
<img alt="http://imagine.gsfc.nasa.gov/Images/features/exhibit/tenyear/future_universe.jpg" class="decoded" src="http://imagine.gsfc.nasa.gov/Images/features/exhibit/tenyear/future_universe.jpg" height="307" width="400" /><br />
<br />
This plot shows the "scale factor" - roughly speaking, the size of some patch of the universe, as a function of time.The universe described by this model fits extremely well with the observations of distant galaxies, supernovas, quasars, etc.<br />
<br />
If the early universe is indeed radiation dominated, then the scale factor goes to zero at some finite time in the past: that is, there is a Big Bang - an initial singularity.<br />
<br />
However, we now have an alternative account of the earliest moments of the universe. Inflationary cosmology, proposed by Alan Guth in 1980, then in a corrected from by Linde and (independently) by Albrecht and Steinhardt in 1982 supposes that <i>before</i> the radiation-dominated epoch there was another epoch, dominated by a cosmological constant - but a very much larger cosmological constant than the one we measure now. I'm not going to go into the reasons these physicists thought there might have been a very large cosmological constant in the early universe, which then "switched off" (meaning it wasn't really a "constant", obviously): you can <a href="http://en.wikipedia.org/wiki/Cosmic_inflation" target="_blank">read about it at the Wikipedia page</a> if you're interested.<br />
<br />
The inflationary model was able to explain several features of the universe that had been puzzling in earlier cosmological models: the flatness problem, the horizon problem, and the monopole problem. In science, though, explanatory power is not enough for a theory to become accepted. In addition, a theory has to make <i>novel predictions</i> that are <i>confirmed by experiment</i> before scientists accept it as (likely to be) true.<br />
<br />
(I can't help pointing out how different this is from theistic "explanations," in which God is claimed to be the explanation of things like life, morality, or the universe, but where there is no concern for making testable predictions about these realms.)<br />
<br />
We now have several good reasons to think that there was in fact such an inflationary epoch. One of these is the pattern of fluctuations of the cosmic microwave background, that fits extremely well with the predictions of inflation:<br />
<br />
<img alt="graph.png" class="jive-image" src="https://community.emc.com/servlet/JiveServlet/downloadImage/38-3151-27041/graph.png" style="display: block; margin-left: auto; margin-right: auto;" /><br />
<br />
Another is the <a href="https://medium.com/starts-with-a-bang/25c5d719187b" target="_blank">very recent BICEP2 result</a>, that seems to show the effects of quantum gravity on the polarization of the cosmic microwave background, in a way consistent with the predictions of the inflationary model.<br />
<br />
So inflationary cosmology replaces the initial singularity with a period of exponential expansion.<br />
<br />
<img src="http://inspirehep.net/record/1255034/files/taLOGLOG.png" height="280" width="400" /> <br />
<br />
How long is this inflationary period? Well, an exponential function never reaches zero, so the inflationary period is, in principle, <i>infinitely long!</i><br />
<br />
Let's sum that up:<i> <b>According to our best, experimentally verified model of cosmology, the universe is infinitely old and has no initial singularity!</b> </i> <br />
<br />
This is the current state of our understanding of the early universe. Now, I have to admit right away that no physicist thinks the inflationary model is the end of the story. The exponential expansion is so fast that in a very short time the scale factor reaches the Planck realm, where we expect GR to break down and quantum gravity to come into play. So most diagrams of the early universe insert a quantum gravity region before the inflationary epoch. (In this diagram from Andrei Linde it's labeled "Space Time Foam.")<br />
<br />
<img alt="From a lecture by Andrei Linde (link is in the text): a schematic plot of the size of the universe over time. The extreme left is speculative, the inflationary epoch is the one probed by the recent BICEP2 measurement. " class="size-large wp-image-7527" src="http://profmattstrassler.files.wordpress.com/2014/03/lindebigbangplot.png?w=500&h=361" /><br />
<br />
There has been much discussion of what went on <i>before </i>the inflationary epoch: <a href="http://en.wikipedia.org/wiki/Quantum_foam" target="_blank">quantum foam</a>, the <a href="http://www.einstein-online.info/spotlights/quantum_cosmo_path_integrals" target="_blank">no-boundary proposal</a>, the <a href="http://en.wikipedia.org/wiki/Cyclic_Model" target="_blank">cyclic universe</a>, and so on. There is even a version called "<a href="http://arxiv.org/abs/hep-th/0702178" target="_blank">eternal inflation</a>," in which some portion of the universe goes on inflating forever, while pocket universes like ours bubble off from time to time. In some of these models, time is finite in the past. In others, it is infinite. But all of them are <i>pure speculation</i>: there is to date no experimental confirmation of any of these scenarios.<br />
<br />
Does modern cosmology support the premise that the universe had a beginning? Emphatically, <b><i>no!</i></b> Our best model extends infinitely into the past, with no initial singularity. We know better than to take that prediction as the last word: likewise, we know better than to take models that <i>do</i> exhibit an initial singularity as the last word. In short, modern cosmology allows us to draw no conclusion about whether the universe has existed for a finite or infinite amount of time. And anyone who says differently is not being completely honest.<br />
<br />
Next time: Why the BVG theorem is irrelevant to the Kalam Cosmological Argument! Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com2tag:blogger.com,1999:blog-7164603649660539619.post-52614074789109158652014-03-17T08:49:00.001-04:002014-03-17T08:49:51.513-04:00Facts, Brute and OtherwiseProf. Feser has <a href="http://edwardfeser.blogspot.com/2014/03/can-you-explain-something-by-appealing.html" target="_blank">responded at length</a> to some comments I made on <a href="http://edwardfeser.blogspot.com/2014/03/an-exchange-with-keith-parsons-part-iv.html" target="_blank">one of his posts</a>. As usual, I thank him for his time and attention to my comments.<br />
<br />
In those comments, I proposed the example of lightning striking a tree and starting a forest fire. I claimed that the lightning is still an explanation for the fire, even if the lightning itself was a brute fact (i.e. a fact having no explanation).<br />
<br />
I realized (eventually) that my example was not the sort of explanation Feser had in mind in his original post. My example was a horizontal causal chain, in which one event causes another, which causes another, and so on, while Feser's original claim was about vertical explanatory chains: one level of explanation is in turn given a more detailed description by a lower-level explanation, which is in turn given a still-lower-level explanation. (The picture I have in mind is, for example, of a broken window that is explained at one level by the rock that hit it, but at a lower level by the fracturing properties of glass and the stresses imposed by the rock, and those properties are in turn explained by the properties of the molecules of which the glass and the rock are made, and so on.) So my example wasn't really relevant to Feser's point.<br />
<br />
In his new post, though, Feser clearly <i>does</i> intend his point
to apply to horizontal causal chains, so perhaps the forest fire example
is relevant after all. Let me add a few more remarks.<br />
<br />
For some reason, I'm more sympathetic to the idea that the brutishness of facts propagates vertically. I'm not sure why my intuition differentiates between the horizontal and vertical explanatory chains. The goal of physics is to <i>describe</i> the way the universe is in as simple and efficient a manner as possible. We physicists suppose that everything physical can be explained at
bottom by the Standard Model of elementary particles, but we are content
to take that theory as a brute fact. (Well, not really "content": we
are always striving for a deeper explanation which will explain the
structure and parameters of the Standard Model. But if we found such a
theory, we would take <i>that</i> as a brute fact.) So in some sense the answer to any physical question is, "That's just the way the universe <i>is</i>." But that doesn't mean such explanations aren't useful.<br />
<br />
Any explanation of a fact A will necessarily be in terms of <i>other</i> facts B, C, and D. (Unless A is self-explanatory, whatever that might mean.) B, C, and D, in turn, are either self-explanatory, or brute facts, or they are explained in terms of some further facts E, F, and G. So the whole thing can only bottom out in facts that are either self-explanatory or brute. (It seems to me that this much is true of both vertical and horizontal chains.) <br />
<br />
If I read the professor's remarks correctly, he is saying that something can only be a <i>real </i>explanation if it bottoms out in only self-explanatory facts. (And that this is true of both vertical and horizontal explanatory chains.)<br />
<br />
My response is that, if this is true, then there are hardly any examples of real explanations. In fact, maybe there has never been a real explanation in the history of humanity. For (nearly?) all actual explanations leave something else unexplained.<br />
<br />
For instance:<br />
<ul>
<li>I can explain why that pot of water is boiling by noting that it has been on a hot burner for 15 minutes. </li>
<li>I can explain why the window broke by noting the rock that hit it.</li>
<li>I can explain why I slipped and fell by noting the ice on the sidewalk.</li>
</ul>
People do not normally require a deeper explanation in order to consider these real explanations. I do not need to understand the molecular structure of water and its relation to the boiling point in order to consider the hot stove to be the explanation for the boiling pot. I don't need to know about the breaking stress of glass to consider that the rock explains the broken window. I don't need to understand how ice lowers the coefficient of friction to think the ice explains why I slipped. <br />
<br />
What I'm saying is, any <i>actual</i> example of an explanation <i>always</i> leaves some loose ends. The regularities themselves are enough for us to claim we have an explanation: heat boils water, rock breaks window, ice makes sidewalks slippery.<br />
<br />
Now, what Feser seems to be saying is that, though we might not know what the explanation is for the explaining facts B, C, and D, we must at least believe that <i>there is</i> an explanation for those facts. Otherwise we don't really have an explanation. <br />
<br />
To this I can only respond as <a href="http://www.patheos.com/blogs/secularoutpost/2014/03/05/reply-to-prof-fesers-response-part-iv/" target="_blank">Keith Parsons did</a>: I don't see why I should think this. If all actual examples of explanations leave something else unexplained, why should I deny that these are true explanations? It makes more sense to me to provide an account of explanation that reflects how we actually use explanations than to provide an account which declares by fiat that no real-world examples of explanation are <i>true</i> explanations.<br />
<br />
Feser challenged me to provide an alternative account of explanation. I have done so before in previous discussions, and have not to my recollection had a response, but I am happy to repeat it here.<br />
<br />
Consider the <a href="http://plato.stanford.edu/entries/scientific-explanation/#2" target="_blank">D-N model of scientific explanation</a>. According to this model, an explanation of an event A consists of two things:<br />
<ol>
<li>A list of natural laws L1, L2, L3....</li>
<li>A list of conditions C1, C2, C3.... that guarantee the laws apply in the case A. </li>
</ol>
So we can provide a D-N explanation of the forest fire as follows:<br />
<ol>
<li>L1: Lightning causes fires. </li>
<li>C1: There was a lightning strike.</li>
</ol>
Under the D-N model, the lightning strike <i>is</i> an explanation of the forest fire, even if we have no explanation of the lightning itself (i.e, it was a brute fact).<br />
<br />
Let's return to the boiling pot. I can, in principle, carry my explanatory chain vertically downward, explaining the molecular properties of water in terms of the quantum mechanical properties of the atoms, and the properties of the atoms in terms of the Standard Model. There I bottom out in brute facts, from my physicist's point of view.<br />
<br />
So here's my counter-challenge for Professor Feser: give a <i>real</i> explanation - in his own sense - of why the water is boiling: an explanation that bottoms out only in self-explaining facts or necessary truths.<br />
<br />
Finally let me note that scientific explanations of the kind I've been talking about have a stunning record of success. Engines, TVs, computers, cell phones - all of modern technology stems from our ability to explain things in terms of unifying regularities. In contrast, Aristotelian explanation has been around for more than 2000 years: what practical successes can it claim?Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com4tag:blogger.com,1999:blog-7164603649660539619.post-57572520409350992702014-03-14T15:10:00.000-04:002014-03-14T15:10:06.755-04:00Ancient Stone Tools Discovered to Have Traveled 250 Light-years!I just discovered <a href="http://what-if.xkcd.com/86/" target="_blank">xkcd: What If</a>?<br />
<br />
I'm very happy now.Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com0tag:blogger.com,1999:blog-7164603649660539619.post-9893857730562650672014-03-04T09:54:00.001-05:002014-03-04T09:54:16.432-05:00Bicycles and UniversesI have often imagined debating William Lane Craig myself, and thought out the ways I would respond to his arguments. I have often, while listening to Craig's debates, wondered why his opponent didn't call him on some claim that was simply untrue. Were they just being polite, or did they not realize the falsity of the claim?<br />
<br />
I think I may be cured of these fantasies. Sean Carroll did brilliantly in <a href="http://www.youtube.com/watch?v=PXdYtAwH33k" target="_blank">the debate</a> - far better than I could ever have done. He didn't hesitate to say outright, "That's just false!" And his deep expertise in cosmology was the perfect counterpoint to Craig's quote-mining of partially-understood physics papers. <br />
<br />
I have only a couple of comments on style and content. I thought Sean did a good job of pointing out where Craig failed to respond to the argument. (This is an area where Craig usually excels.) But instead of merely pointing it out, he ought to have taken the opportunity to summarize his argument again, for those who might not have understood it completely the first time.<br />
<br />
Craig, as usual, excelled in his logical organization and presentation of his argument. His concluding summary nicely recalled his original point: not that he was out to prove God's existence, but that modern cosmology lends support to one of his premises.<br />
<br />
Here Carroll really missed an opportunity. He ought to have said, briefly and succinctly, that modern cosmology lends no support at all the premise that the universe had a beginning. What we can say for sure is that the universe was a very different place 13.7 billion years ago. But any statement about what happened before that is very speculative and unfounded in established science. There are models in which time has a beginning, and there are models in which it doesn't: none of these models are established science, and so nothing can be deduced from them about a beginning.<br />
<br />
One final missed opportunity: when Craig asked, quite reasonably, "If universes can just pop into existence, why not bicycles? What's the difference?" (from memory, not an exact quote) Sean could have responded that there is an obvious and crucial difference: bicycles are things that exist <i>within time</i>, while universes are not. On the contrary, time exists within a universe. For all Craig's bluster about simultaneous causation in the Q&A session, causality has to do with what brings about a change. And for there to be change, there must be time. Since a universe is not something that happens in time, the causality issue doesn't apply. <br />
<br />
I think Sean probably had something like this in mind in his argument about the a cosmological model as a self-contained description needing no outside cause, but it would have been nice to respond to Craig's question with a specific difference that clearly matters.Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com4tag:blogger.com,1999:blog-7164603649660539619.post-74115865989704775692014-03-03T17:06:00.000-05:002014-03-03T17:07:15.720-05:00Craig, Carroll, and CauseSince I've been reading about causes, one part of <a href="http://www.youtube.com/watch?v=PXdYtAwH33k">the debate</a> that stood out for me was the fact that neither Carroll nor Craig tried to define "cause." In terms of the debate, this was undoubtedly wise: a long digression on the different definitions of "cause" would probably have lost most of the audience. But it was bad philosophy. Carroll tried to explain that, for a physicist, having a consistent mathematical model that comports with the experimental evidence is all we need. Any discussion of causes and effects will proceed from that model. Craig simply kept repeating his <a href="http://www.trulyfallacious.com/logic/logical-fallacies/relevance/argument-from-personal-incredulity">argument from incredulity</a>: a universe can't just pop into being without a reason.<br />
<br />
But certainly, how we think about causation affect our ideas on whether a self-contained universe needs a cause.<br />
<br />
(By the way, this issue is independent of whether the universe in question has a beginning or not. While it might seem intuitively that a universe that begins is more guilty of "just popping" into existence, it has often been argued that a universe that is infinite in time is no less in need of some sort of external cause or explanation.)<br />
<br />
On <a href="http://en.wikipedia.org/wiki/Causality#After_the_Middle_Ages">Hume's regularity view</a>, causation is a matter of constant conjunction: to know that A causes B, we need to know that A is always followed by B. So what we need to do is to make lots of observations of deities, and if "Let there be light!" is always followed by a universe popping into existence, then we can conclude that gods cause universes.<br />
<br />
On <a href="http://plato.stanford.edu/entries/causation-process/#SalMarTraThe">Wesley Salmon's analysis</a>, a causal process is one that can carry some sort of a mark that transmits from the cause to the effect. It would seem, though, that if God is perfect, God is impossible to mark. Thus, we could never tell if a mark can be passed to the universe.<br />
<br />
<a href="http://plato.stanford.edu/entries/causation-process/#ConQuaThe">Another modern approach</a> is to take causation to involve the transmission of a conserved quantity, like energy or momentum. But neither the theist not the atheist would claim that a universe that has a beginning in time was initiated by a transfer of pre-existing energy, so in this case there is no possibility of a cause.<br />
<br />
On the <a href="http://edwardfeser.blogspot.com/2012/05/oerter-contra-principle-of-causality.html">Aristotelian-Thomian analysis</a>, causation involves a potentiality becoming actuality, and an external cause is necessary to tip something into actuality. A universe is obviously possible (if it were impossible we wouldn't be here), so on this analysis an external cause <i>is</i> needed to make the universe actual.<br />
<br />
So it seems possible, in principle at least, that <i>both</i> Craig and Carroll are right: differing definitions of "cause" may yield different conclusions about whether a self-contained universe requires a cause.Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com5tag:blogger.com,1999:blog-7164603649660539619.post-23398578066237796362014-02-25T21:02:00.000-05:002014-03-02T07:02:33.118-05:00Two DebatesThere have been two very recent debates between high-profile Christians and scientifically-minded opponents. <br />
<br />
I'm not that interested in the <a href="http://www.youtube.com/watch?v=z6kgvhG3AkI" target="_blank">Ken Ham vs. Bill Nye the Science Guy debate</a>, as Ham's creationist views have no credibility whatsoever. It would be interesting to see what approach Bill took. <a href="http://whyevolutionistrue.wordpress.com/2014/02/05/who-won-the-big-evolutioncreation-debate/" target="_blank">Some reviews</a> have been positive, <a href="http://www.thedailybeast.com/articles/2014/02/05/the-bill-nye-ken-ham-debate-was-a-nightmare-for-science.html" target="_blank">others</a> not so.<br />
<br />
I'm much more interested in the William L. Craig vs. Sean Carroll debate. Unfortunately, there doesn't seem to be video available for it yet. [ETA: Video now available <a href="http://www.youtube.com/watch?v=PXdYtAwH33k">here.</a>] WLC is infamous in atheist circles for <a href="http://commonsenseatheism.com/?p=392" target="_blank">"winning" most of his debates</a>. ("Winning" is of course very subjective in informal debates like these, but when the folks on the opposing side think you won, you probably won.) Carroll is not only a cosmology expert, he is one of the most philosophically astute scientists I know of - he's light-years ahead of Lawrence Krauss or Jerry Coyne, in my opinion. So Carroll is probably the ideal opponent for WLC. Props to WLC for taking on Carroll on his home turf: cosmology. This was either very brave or very stupid of him.<br />
<br />
Carroll's own views on the debate are <a href="http://www.preposterousuniverse.com/blog/2014/02/24/post-debate-reflections/" target="_blank">here</a>. (I don't see any comments on it on <a href="http://www.reasonablefaith.org/" target="_blank">Craig's website</a> yet.) I think it's not just atheistic bias to assume that, where they disagree on the cosmology, the cosmology expert is probably right.<br />
<br />
One new thing I learned from Sean's comments: Some cosmologies have a <a href="http://en.wikipedia.org/wiki/Boltzmann_brain" target="_blank">Boltzmann Brain problem</a> and others don't. That's something I'll have to learn more about. <br />
<br />
Craig has employed modern cosmology extensively in the past, both in debates and in his published papers. I was glad to see that Sean brought up the big problem with this: some cosmological models have an infinite past. Others don't. None of these models is considered established physics. So cosmology tells us nothing (yet!) about whether the universe had a beginning or not.<br />
<br />
I really like Sean's five responses to the fine tuning argument - especially his #2, which is basically the same as my <a href="http://somewhatabnormal.blogspot.com/2013/06/more-detuning.html" target="_blank">Fine Tuning Argument for Naturalism</a>. Craig apparently had no response to this point.<br />
<br />
There's been a lot of discussion about whether these debates are a good idea or not, from the point of view of promoting science and rational thought, much of it focussed on whose resume will be enhanced and whose pockets will be filled. From the purely intellectual point of view, I'm all for them. It's true that debates are a poor format for getting to the truth, but they're a great format for exposing folks to ideas they might not have encountered otherwise. Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com5tag:blogger.com,1999:blog-7164603649660539619.post-67437055385016169502014-02-22T08:37:00.000-05:002014-02-22T08:37:04.225-05:00Evolution and Entropy, AgainI just got an email from someone who had read <a href="http://physics.gmu.edu/~roerter/EvolutionEntropy.htm" target="_blank">my essay about evolution and the second law of thermodynamics</a> and thought he had found a flaw in it. It made me realize that the discussion there is rather technical and mathematical, and I ought to write up the basic idea in a clear and non-mathematical way. So here goes.<br />
<br />
The thermodynamic argument against evolution goes something like this:<br />
<ol>
<li>Evolution involves an increase of order, and therefore a decrease of entropy.</li>
<li>The second law of thermodynamics says that entropy never decreases.</li>
<li>Therefore, evolution contradicts the second law of thermodynamics.</li>
</ol>
Let's first consider (1.). In order to establish this, one would have to show that the body of a human being has less thermodynamic entropy than an equal mass of bacteria (for instance). Now, this may in fact be true, but n<i>o one has ever proven such a thing</i>, to my knowledge. Without proving (1.), the argument can't get off the ground.<br />
<br />
Secondly, <i>even if (1.) is true</i>, the argument fails, because (2.) is wrong: the second law of thermodynamics <i>doesn't</i> say that entropy never decreases.<br />
<br />
In fact, entropy decreases spontaneously in lots of natural settings: for instance, when a pond freezes over in winter. Ice has much less entropy than liquid water - if it were impossible for entropy to decrease then it would be impossible for ponds to freeze over.<br />
<br />
<img alt="http://blogs.yis.ac.jp/19miyoshiay/files/2012/09/581845029-1uku734.jpg" class="shrinkToFit decoded" src="http://blogs.yis.ac.jp/19miyoshiay/files/2012/09/581845029-1uku734.jpg" height="304" width="400" /><br />
<br />
So what <i>does</i> the second law of thermodynamics say? It says that there can't be a decrease of entropy in one place without a compensating <i>increase</i> of entropy somewhere else. In the case of the pond, the heat escaping from the water during the freezing process causes an increase of entropy of the air over the pond.<br />
<br />
If you wanted to prove that the freezing of the pond violates the second law of thermodynamics, you would have to calculate the entropy decrease of the water, calculate the entropy increase of the air, and show that the latter is less than the former.<br />
<br />
In the case of evolution, you would have to calculate the entropy decrease due to cells being "organized" into higher life forms, which, we already noted, has never been done. Then you would have to show there was no compensating increase of entropy elsewhere. This second step is what I addressed in my essay. If we take the whole Earth as our system, then we find there is an absolutely <i>enormous</i> increase of entropy due to the radiation of heat energy into space. This entropy increase is so large that no possible decrease of entropy due to evolution would cause a violation of the second law of thermodynamics. Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com0tag:blogger.com,1999:blog-7164603649660539619.post-3526479241193574982014-02-12T13:32:00.000-05:002014-02-12T13:32:51.962-05:00Victor, Meet KenVictor Reppert's blog, <a href="http://dangerousidea.blogspot.com/" target="_blank">Dangerous Idea</a>, has been on my blogroll for a while. I try to look for blogs that express the theist's viewpoint in an intelligent manner, and Reppert is a Christian who has some philosophical acumen and whose arguments have often seemed worthy of consideration. Recently, though, his posts have been declining in both length and quality. Now he has hit a new low. Here's a <a href="http://dangerousidea.blogspot.com/2014/02/god-authority-and-electrons.html" target="_blank">recent post</a>, in its entirety:<br />
<br />
<blockquote class="tr_bq">
<div style="background-color: white; color: #333333; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 13px; line-height: 20px; margin-bottom: 10px;">
Atheists often make the claim that the burden of proof lies with the
believer, not the unbeliever. They would ask whether you can prove that
the nonexistence of anything. Rather, it should be up to the person who
makes the positive claim to provide proof, not the people trying to
prove a negative. </div>
<div style="background-color: white; color: #333333; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 13px; line-height: 20px;">
However, there are many things that are invisible that I might have
trouble proving. Let's take electrons, for example. I've never seen one
myself. Many people believe in them simply on the authority of
scientists. People also believe in God, even though they can't see God,
because they take his existence on the basis of authorities. What's the
difference? </div>
</blockquote>
Here's the difference, Victor: anyone who disbelieves the authorities can repeat the experiments on their own. Electrons, you say? How about the <a href="http://en.wikipedia.org/wiki/Oil_drop_experiment" target="_blank">Millikan oil drop experiment</a>, the <a href="http://en.wikipedia.org/wiki/Compton_scattering" target="_blank">Compton effect</a>, the <a href="http://www.nyu.edu/classes/tuckerman/adv.chem/lectures/lecture_3/node1.html" target="_blank">q/m experiment</a>, the <a href="http://en.wikipedia.org/wiki/Franck%E2%80%93Hertz_experiment" target="_blank">Franck-Hertz experiment</a>? How about examining the <a href="http://en.wikipedia.org/wiki/Fine_structure" target="_blank">fine structure of hydrogen</a>? If you're unsure about electrons, try one of these experiments and see what you get. I've done several of them myself, and can vouch for the results.<br />
<br />
<i>Of course</i> it's up to the person making the claim to provide the proof. And scientists have done that - and published their results - and repeated those demonstrations again and again for generations of students. <br />
<br />
Please tell me, Victor, how do I go about repeating the results of the religious "authorities"? <br />
<br />
You can go to a Chinese physicist, a Russian physicist, a South African physicist, a Brazilian physicist, an Australian physicist, and ask them the charge of the electron, and they will all give you the same answer.<br />
<br />
If I go to a Hindu religious authority, a Muslim religious authority, a Roman Catholic religious authority, a Sikh religious authority, a Buddhist religious authority, and a Shinto religious authority, will they give me the same answer to my religious questions?<br />
<br />
Whole industries now rely on our understanding of electrons. Every time you make a phone call, watch TV, or type a blog post, you are effectively performing an experiment that confirms the properties of electrons. We trust that understanding enough to stake our very lives on it, every time we get on a plane, train, or automobile. <br />
<br />
What discoveries or declarations of religious authorities are so reliable that people all over the world stake their lives on them?<br />
<br />
<br />
<img alt="http://www.godofevolution.com/wordpress/wp-content/uploads/2014/02/Ham-Nye-debate-in-a-nutshell-via-exploring-our-matrix.jpg" class="decoded" src="http://www.godofevolution.com/wordpress/wp-content/uploads/2014/02/Ham-Nye-debate-in-a-nutshell-via-exploring-our-matrix.jpg" height="230" width="400" /><br />
<br />
"What's the difference," you ask?<br />
<br />
One word: <b>EVIDENCE</b> Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com3tag:blogger.com,1999:blog-7164603649660539619.post-46840223520187280172014-02-08T13:01:00.000-05:002014-02-08T13:01:08.043-05:00Against CauseIn an attempt to gain a better understanding of modern views of causation, I've been reading <i>Causation and Explanation</i>, by Stathis Psillos. So far what I've learned is this: modern views of causation are a mess. There are intrinsic and extrinsic views, reductive and non-reductive views, the "marker" view, and the "conserved quantity" view. There is no agreement on whether Hume's regularity view of causation needs to be improved upon, or abandoned and replaced with something quite different.<br />
<br />
Over at The Edge, there is the annual <a href="http://www.edge.org/responses/what-scientific-idea-is-ready-for-retirement" target="_blank">Edge Question event</a>. This year's question: What scientific idea is ready for retirement? Go read the responses, they're very interesting and very short. <br />
<br />
Among the responses, <a href="http://www.edge.org/response-detail/25435" target="_blank">W. Daniel Hillis suggests</a> we retire the concept of cause and effect. Causes, he suggests, are just parts of a story we tell about the world.<br />
<br />
<blockquote class="tr_bq">
Science is a rich source of powerful explanatory stories. For
example, Newton explained how a force causes a mass to accelerate. This
gives us a story of how an apple drops from a tree or a planet circles
around the Sun. It allows us to decide how hard the rocket engine needs
to push to get it to the Moon. Models of causation allow us to design
complex machines like factories and computers that have fabulously long
chains of causes and effects. They convert inputs into the outputs that
we want.</blockquote>
These stories can be very useful, but they can also be misleading.<br />
<blockquote class="tr_bq">
It is tempting to believe that our stories of causes and effects are
how the world works. Actually, they are just a framework that we use to
manipulate the world and to construct explanations for the convenience
of our own understanding. </blockquote>
<br />
So maybe the reason philosophers can't find a decent characterization of causes is that they are not really a part of the universe. Rather, they are something we invent - maybe in a rather haphazard and inconsistent manner - to help us track important aspects of the world around us. Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com1tag:blogger.com,1999:blog-7164603649660539619.post-79379285306670633032014-02-06T21:06:00.001-05:002014-02-06T21:06:43.019-05:00Where's Evil?<blockquote class="tr_bq">
Where's evil? It's that large part of every man that wants to hate without limit, that wants to hate with God on its side. </blockquote>
<br />
(Kurt Vonnegut, <i>Mother Night</i>) Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com1tag:blogger.com,1999:blog-7164603649660539619.post-36868966771567764322014-01-11T10:12:00.000-05:002014-01-11T10:12:26.368-05:00I've Also Got a Nice Bridge For Sale....<br />
<div style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;">
<a href="http://wp.patheos.com.s3.amazonaws.com/blogs/exploringourmatrix/files/2014/01/Sagan-Buying-Used-Religion-1.png" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img alt="" border="0" class="alignnone size-full wp-image-20492" height="331" src="http://wp.patheos.com.s3.amazonaws.com/blogs/exploringourmatrix/files/2014/01/Sagan-Buying-Used-Religion-1.png" width="590" /></a> </div>
<div style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;">
<br /></div>
<div style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;">
Thanks, <a href="http://www.patheos.com/blogs/exploringourmatrix/2014/01/advice-for-those-buying-a-used-religion-2.html" target="_blank">James</a>.</div>
<br />
<br />
<br />
Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com0tag:blogger.com,1999:blog-7164603649660539619.post-65239397266222582512013-12-22T13:42:00.000-05:002013-12-22T13:42:30.647-05:00Physics Lies!I've been bashing the theists for a while, so I'm going to take a break and bash an atheist for a change.<br />
<br />
Nancy Cartwright is the author of <i>How the Laws of Physics Lie</i>, and is apparently an influential philosopher. Kitcher mentions her in his <a href="http://opinionator.blogs.nytimes.com/2013/09/08/things-fall-apart/?ref=opinion&_r=3" target="_blank"><i>Mind and Cosmos</i> review</a>, she is regularly included in anthologies of important papers in the philosophy of science, and her term "Dappled World" (borrowed from Manley Hopkins, according to Kitcher) seems to have become a sort of rallying point for modern philosophical views of science.<br />
<br />
I think her work is shoddy and unconvincing. <br />
<br />
OK, choosing that title for her book is like waving a cape in front of a bull, I suppose. But I really tried to give her a fair hearing, honest I did. Readers of this blog can, I suppose, judge how good I am at giving a fair hearing to views I disagree with. But let me try to present her argument before I tear it apart.<br />
<br />
<b>The Laws of Physics Lie</b> <br />
<br />
In Essay 3 of the book, Cartwright lays out the case that the laws of physics are not true, or, to the extent they are true, they are not interesting. In fact, they are not even <i>approximately </i>true. Why?<br />
<br />
She illustrates with Newton's law of universal gravitation. For the definition of this law she quotes Feynman:<br />
<br />
<blockquote class="tr_bq">
(NG1)<i> The Law of Gravitation is that two bodies exert a force between each other which varies inversely as the square of the distance between them, and varies directly as the product of their masses.</i></blockquote>
Then she asks, and answers:<br />
<br />
<blockquote class="tr_bq">
<i>Does this law truly describe how bodies behave?</i><br />
<i><br /></i>
<i>Assuredly not.</i></blockquote>
Why not? Well, she says, two bodies may have electric charges, and so the force exerted by one on the other is given neither by NG1 nor by Coulomb's law of electric force, but by a combination of the two. Therefore<br />
<br />
<blockquote class="tr_bq">
<i>These two laws are not true: worse, they are not even approximately true.</i></blockquote>
<br />
For instance, in an atom, the law of gravitation is swamped by the Coulomb force and so the former is not even approximately true.<br />
<br />
Notice that she is not complaining about extreme cases where Newtonian gravitation must be replaced by General Relativity. Her complaint is that the law doesn't state a fact: except, perhaps, in a universe completely empty except for two uncharged objects.<br />
<br />
She considers an alternate version of NG1 that uses a prefatory clause to correct the deficiency:<br />
<br />
<blockquote class="tr_bq">
(NG2) <i><b>If</b> there are no forces other than gravitational forces at work, <b>then</b> two bodies exert a force between each other which varies inversely as
the square of the distance between them, and varies directly as the
product of their masses.</i></blockquote>
<br />
This, she allows, may be a true law, but it is not a very interesting one, for in reality objects have both kinds of properties (mass and electric charge) and so NG2 has no (or very few) applications in reality.<br />
<br />
From a physicist's point of view, this is all very wrong-headed. First of all, since she is talking about combining different influences, the law she ought to be talking about is Newton's second law of motion:<br />
<br />
<blockquote class="tr_bq">
(NA)<i> The acceleration of an object is proportional to the net force and inversely proportional to its mass.</i></blockquote>
Somehow, she completely avoids mentioning this law anywhere in the chapter (though she mentions it obliquely in considering a related objection, as we will see below). Since she doesn't mention NA, I don't know whether she considers this one of laws that is not even approximately true. But you can't talk about gravitational and electric forces combining without it. With this framework in mind, there is an obvious alternative to NG1 and NG2:<br />
<br />
<blockquote class="tr_bq">
(NG3)<i> For two massive bodies, <b>there is a contribution to the net force</b> that varies inversely as
the square of the distance between them, and varies directly as the
product of their masses.</i></blockquote>
<br />
With this change, I submit, we have a law that is at least approximately true, with no further need of <i>ceteris paribus</i> clauses.<br />
<br />
This is such a simple solution to Cartwright's difficulty that it's hard to believe she missed it. However, she does go on to discuss the law of vector composition of forces, and then to consider a suggestion of Lewis Creary that is similar to NG3. Let's consider what she has to say about these issues.<br />
<br />
<b>Vector Addition</b><br />
<br />
Cartwright admits that physicists have an answer to the question of combining forces: she calls it the "vector addition story."<br />
<br />
<blockquote class="tr_bq">
<i>The vector addition story is, I admit, a nice one. But it is just a metaphor. <b>We</b> add forces... when we do calculations. Nature does not 'add' forces.For the component forces are not there, in any but a metaphorical sense, to be added....</i></blockquote>
For Cartwright, the individual component forces are not real. Only the net force is real.<br />
<br />
But this is quite obviously false. Consider, for example, a spring that is subject to equal and opposite forces on its two ends:<br />
<br />
<img class="rg_i" data-src="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSLGTzTDT5x0Xhcs4L42XGAiGOL_7vUO0uMTSpu4vsQqgKeJ4-V" data-sz="f" name="KtHozyx74esOjM:" src="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSLGTzTDT5x0Xhcs4L42XGAiGOL_7vUO0uMTSpu4vsQqgKeJ4-V" style="height: 199px; margin-left: -2px; margin-right: -6px; margin-top: 0px; width: 227px;" /><br />
The net force is zero, so the center of mass of the spring doesn't accelerate. But the spring is <i>compressed</i> - the component forces have a real, physical effect.<br />
<br />
Try telling this guy that the component forces aren't real:<br />
<img class="irc_mut" height="228" id="irc_mi" src="http://images.morris.com/images/lubbock/mdControlled/cms/2008/09/21/334829060.jpg" style="margin-top: 10px;" width="320" /><br />
<br />
Cartwright is essentially saying "'two apples plus one apple equals three apples' can't be true, because if the two apples and the one apple are real, <i>and</i> the three apples are real, then I would have six apples, not three." But this is just silly: two apples plus one apple equals three apples because that's simply what addition means, when applied to apples. Similarly, in the vector addition of forces, two real, occurrent forces can be added to make a real net force, because that's simply what it means to combine two forces.<br />
<br />
For this, Cartwright deserves an award for Worst Misuse of Mathematics By a Professional Philosopher Not Named Craig.<br />
<br />
<b>Causal Action</b><br />
<br />
Cartwright then turns to Creary, who claims that there are two types of physical laws: laws of causal influence and laws of causal action. Though she doesn't say so, in Newton's mechanics, the law of causal action is good old F = ma (NA).<br />
<br />
<blockquote class="tr_bq">
<i>On Creary's account, Coulomb's law and the law of gravity come out true because they correctly describe what influences are produced.... The vector addition law then combines the separate influences to predict what motions will occur.</i> </blockquote>
<blockquote class="tr_bq">
<i> This seems to me to be a plausible account of how a lot of causal explanation is structured. But as a defence of the truth of fundamental laws, it has two important drawbacks. First, in many cases there are no <b>general</b> laws of interaction... In fact, classical mechanics may well be the only discipline where a general law of action is always available.</i></blockquote>
<br />
Apparently Cartwright doesn't know about quantum mechanics, where Schroedinger's equation gives a general law, or quantum field theory, where the Lagrangian path integral does the same. <br />
<br />
Anyway, it makes no sense to claim that there are no true fundamental laws of physics, except for those few cases where the laws are both fundamental and true. Naturally, if there are general laws of action, and if physics is a more or less unified subject, then we would expect the general laws to be few. The fact that there are only a few such fundamental laws actually shows the strength of the reductionist thesis rather than the opposite.<br />
<br />
On the other hand, if her point is just that most of the time, working physicists are not dealing with the fundamental laws, but with some approximations to them, or phenomenological laws that are not fundamental, then I would agree with her, but find the point trite and uninteresting. These physicists wouldn't ever claim that their approximations are true in all cases. <br />
<br />
Actually, Cartwright <i>does</i> know about quantum mechanics, because in the very next section she discusses a quantum example: the spectrum of a carbon atom. What she says here is so pathetic that I can't bear to grind through it point by point. Essentially, she again ignores the general law of action (Schroedinger's equation) in order to make her point that there is no general law of action.<br />
<br />
At first I thought Cartwright had simply not bothered to understand the physics before she began drawing philosophical conclusions. But later in the book she shows a detailed understanding of some much more difficult areas of physics, so that doesn't seem to be the problem. <br />
<br />
The only other explanation I can think of for these egregious errors is that Cartwright is working with a pre-conceived agenda, such that all the examples are contorted so as to support her thesis. <br />
<br />
This is no way to ground a philosophical world view.Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com3tag:blogger.com,1999:blog-7164603649660539619.post-40761118401699902082013-12-19T20:27:00.000-05:002013-12-19T20:27:41.807-05:00A Natural ReductionOne of the great advantages of the naturalist world view is how it all hangs together. The workings of the mind can be explained in terms of the workings of the brain, which can be explained in terms of the workings of the brain cells, which can be explained in terms of the electrical and chemical properties of molecules, which can be explained in terms of the physical properties of the particles of which those molecules are composed. And the same goes for anything else in the universe: stars, moons, clovers....<br />
<br />
Now, I will admit that some of the links in that proposed chain of explanation are not as strong as others: the mind-brain link, for example. But the overall scheme seems sound, and the naturalistic world view can count innumerable successes as evidence of its truth: the technologies of transportation, agriculture, communication, medicine, and psychiatry, to mention just a few. Put this against the abject <i>failure</i> of alternative ways of thinking: what did Christianity (just to pick on one alternative) accomplish in the 1500 years before scientific thinking arose?<br />
<br />
At any rate, even when precise explanations are lacking, there doesn't seem to be any strong argument why the gaps cannot be filled out in a naturalistic way.<br />
<br />
It seems, though, that many atheist philosophers are no longer satisfied with this reductionistic picture. The recent book <i>Mind and Cosmos</i>, by atheist philosopher Thomas Nagel, argues that there are aspects of subjective experience that can't be explained by reductionistic means. (<a href="http://opinionator.blogs.nytimes.com/2013/08/18/the-core-of-mind-and-cosmos/" target="_blank">Short version here</a>.) Another atheist philosopher, Philip Kitcher, whom I have the greatest respect for, <a href="http://opinionator.blogs.nytimes.com/2013/09/08/things-fall-apart/?ref=opinion&_r=3" target="_blank">disagrees with Nagel</a> but seems to agree that the reductionist program has not accomplished the task it set out to do. "Unity fails at both ends," writes Kitcher.<br />
<br />
For once, I agree with <a href="http://edwardfeser.blogspot.com/2013/10/philip-kitcher-bait-and-switcher.html" target="_blank">Professor Feser</a>: if naturalism fails to give us a unified picture of everything, then it is time to abandon naturalism and seek a different explanation, rather than to cling to a failed program.<br />
<br />
But I am not as pessimistic as these philosophers. Perhaps that's merely ignorance on my part. But some of the anti-reductionist arguments I've come across seem just silly, and, as I already said, there don't seem to be any good arguments for the <i>impossibility</i> of naturalistic explanation. I remain a hard-core reductionist, and I'm going to try to defend that view.<br />
<br />
Next: Do the laws of physics lie?Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com36tag:blogger.com,1999:blog-7164603649660539619.post-83397602878984488972013-11-26T09:06:00.000-05:002013-11-26T09:33:22.203-05:00Determined by What?Kripke is central to Ross's argument, and it is certainly true that both Ross and Kripke take his point to be a metaphysical (not just an epistemological) one, so it is fair of Professor Feser to require a more detailed argument that the one I gave in my <a href="http://somewhatabnormal.blogspot.com/2013/10/against-physicalism.html" target="_blank">first post</a> on Ross. I still think that what I wrote there was basically correct, and that Feser has not adequately countered my objection. But let me try to say it again, more clearly and (I hope) convincingly.<br />
<br />
I was helped immensely in my understanding of the structure of Kripke's argument by a <a href="http://www-bcf.usc.edu/~soames/sel_pub/#Skepticism" target="_blank">critical response to Kripke by Scott Soames</a>. In an intricate bit of philosophical analysis, Soames shows that Kripke is equivocating between two different meanings of "determine." I think Ross is making a similar, but more basic, mistake, as I will explain.<br />
<br />
What does it mean for a set of facts (F) to determine another set of facts (G)? This is the fundamental issue of determinacy. In order to be clear about Ross's argument, we need to know what he thinks F is, what he thinks G is, and what he means by "determine." For Soames, the problem lies in the last of these. For Ross, it lies in the other two.<br />
<br />
The first thing we have to get clear is that Ross is <i>not</i> talking about the indeterminateness of <i>meaning</i>, Feser's claims notwithstanding. If he were, he would have to discuss the meaning of "meaning", as Kripke (?) and Soames do. Also, because Kripke's argument leads to skepticism about whether <i>humans</i> ever mean anything, as well as machines, Ross would owe us an account of how he can avoid the skeptical conclusion about humans while affirming skepticism about machines. But he does none of this. Indeed, as one commenter noted at the beginning of the discussion, Ross never mentions "meaning" in the article. Furthermore, neither Ross nor the naturalist thinks an adding machine <i>means</i> anything when it performs an operation, so if meaning were the issue, the entire discussion about the adding machine would be beside the point.<br />
<br />
So the short reply to Ross' use of Kripke is that Ross has divorced the quaddition argument from the Kripkean context. The result is that quaddition becomes simply another version of the problem of limited data. And we have already seen that the problem of limited data helps Ross not at all. If you are convinced of this point, you can skip the rest of this too-long post. What follows simply expands and explains this point.<br />
<br />
Ross never discusses meaning - his discussion is entirely about whether the machine is executing a function, and whether the machine's future outputs are determinate. Let's look again at the way he begins his argument:<br />
<br />
<blockquote class="tr_bq">
Whatever the discriminable features of a physical process may be, there will always be a pair of incompatible predicates, each as empirically adequate as the other, to name a function the exhibited data or process "satisfies." That condition holds for any finite actual "outputs," no matter how many. That is a feature of physical process itself, of change. There is nothing about a physical process, or any repetitions of it, to block it from being a case of incompossible* forms ("functions"), if it could be a case of any pure form at all. That is because<b> </b>the differentiating point, the point where the behavioral outputs diverge to manifest different functions, can lie beyond the actual, even if the actual should be infinite; e.g.,<b> it could lie in what the thing would have done, had things been otherwise in certain ways.</b> For instance, if the function is x(*)y = (x + y, if y < 10<sup>40</sup> years, = x + y + 1, otherwise), the differentiating output would lie beyond the conjectured life of the universe.</blockquote>
And later on:<br />
<br />
<blockquote class="tr_bq">
Secondly, opposed functions that are infinite (that is, are a "conversion" of an infinity of inputs into an infinity of outputs) can have finite sequences, as large as you like, of coincident outputs; they can even have subsequences that are infinitely long and not different (e.g., functions that operate "the same" on even numbers but differently on odd numbers). <b>So for a machine process to be fully determinate, every output for a function would have to occur.</b> For an infinite function, that is impossible. The machine cannot physically do everything it actually does and also do everything it might have done.</blockquote>
And from <i>Thought and World</i><br />
<br />
<blockquote class="tr_bq">
If the machine is not really adding in the single case, no matter how many acutal outputs seem "right," <b>there might eventually be nonsums</b>.</blockquote>
<br />
[Emphasis added]<br />
<br />
I interpret Ross to be saying that what is not determined - his G - is <i>what function the system is computing</i>. Further, on the basis of the preceding quotes, I take it that he cashes out this G in terms of <br />
a) <i>what the system might output at a future time</i>, and<i> </i><br />
<i> </i>b)<i> </i><i>what the system would have output for inputs it might have had, but did not have.</i><br />
<i><br /></i>
Let's consider a system with two inputs, <i>x</i> and <i>y</i>. Then the question is, "Is the output <i>z</i> determined for every possible <i>x</i> and <i>y</i>?"<br />
<br />
Now we come to central question: <i>determined by what</i>? What is Ross's set F - the facts that (fail to) determine the output, <i>z</i>? <br />
<br />
Since we are considering a purely physical system, a prime candidate for F would be the set<br />
<br />
F1: All the physical facts about the system.<br />
<br />
In this case, the question being asked becomes "Is the output <i>z</i> determined by the physical facts about the system, for all possible inputs <i>x</i> and <i>y</i>?" But this is nothing more nor less than the question of physical determinism. In a deterministic world, the set F1 certainly <i>does</i> determine the possible outputs, <i>z</i>, even for cases that the machine hasn't actually computed. Setting aside issues of quantum indeterminacy (which Ross never mentions), it seems that all outputs <i>are </i>determined by F1.<br />
<br />
But F1 is not what Ross has in mind. He never attempts any discussion of physical determinism. Instead, he seems to have in mind something like<br />
<br />
F2: The physical facts that are known about the system at some time T.<br />
<br />
I take this from his talk of the "<i>discriminable</i> features of a physical process" in the first quote above and from his talk of "empirical adequacy," though I have to say that Ross is extremely vague about this.<br />
<br />
If <i>this </i>is Ross's argument - if he is saying "What the system might have done, or will do, is not determined by the physical facts that we know about the system" - then we should simply reply, "So what?" <a href="http://somewhatabnormal.blogspot.com/2013/11/a-pointless-point-about-data-points.html" target="_blank">As we saw already</a> with the problem of limited data, there is no way to argue from an epistemological lack to a metaphysical conclusion.<br />
<br />
There is another possibility: suppose that, instead of the physical facts that are known about the system, what Ross really means is<br />
<br />
F3: All the physical facts that <i>can be</i> known about the system.<br />
<br />
But now we have to be careful. What does is mean to say something "can be known"? Does this mean all the physical facts that can <i>in principle</i> be known about the system? Then F3 is the same as F1 - all the physical facts about the system can in principle be known (barring quantum uncertainty). In that case, there is no reason to think the outputs are undetermined. However, <i>in actual fact</i> we can never know all the physical facts about the system, no matter what set of observations we make. Thus, any given set of observations, no matter how detailed, is consistent with incompatible functions. Does this justify Ross's conclusion? No, because in that case, there is again only an epistemological lack.<br />
<br />
Let me explain the last remark using the example of a computer. The computer seems at first to be a simple counterexample to Ross's claim that the outputs <i>z</i> are not determined by the physical features of the system. For I can look at the program the computer is running (it is encoded physically somewhere in the computer's memory) and <i>see </i>what the function is: I can deduce, for example, what the output <i>would have been</i> for some inputs <i>x</i> and <i>y</i> that the computer has not actually calculated. But (as Feser points out) a wire might burn out or a transistor go bad inside the computer, so that the actual output is not what the computer program would lead us to believe. This is true, but it doesn't really answer the objection. For suppose I insist on a more detailed physical description of the computer: one so detailed that the failure of the wire/transistor is predictable by this description and so is accounted for. Then we see that the indeterminacy was only apparent: the output is in fact determined by this more detailed set of facts. (In this case the computer would be executing something like quaddition, rather than addition.) If we dig deep enough, we will always find <i>some</i> set of physical facts that <i>do</i> determine the output.<br />
<br />
We can now see why Ross is wrong to say that "for a machine process to be fully determinate, every output for a function would have to occur." A sufficiently detailed set of physical facts about the system determines not only what outputs will occur at a future time, but also what outputs would have occurred for other inputs that were not actually submitted to the machine. <br />
<br />
I have gone into this at length because I think it shows both why Ross's argument is so appealing and why it is wrong. For any <i>given</i> set of physical facts about the system, there are infinitely many inequivalent functions compatible with the behavior of the system. But the set of possible observations is not fixed: if we find a particular set of physical facts leaves the outcome undetermined, we can always ask for a more detailed description of the system. For a sufficiently detailed set of physical facts, we find the outcome <i>is</i> determined by those facts. What makes the argument seem reasonable is the slide from a given set of facts, to any possible set of facts, to all physical facts. <br />
<br />
To summarize:<br />
<br />
<ul>
<li>Ross's argument is not about whether meanings are determined by the physical facts about the system, but whether a functional form is determined.</li>
<li>Whether a functional form is determined is cashed out in terms of whether future or counterfactual outputs are determined.</li>
<li>Ross is unclear about what F it is that fails to determine the functional form.</li>
<ul>
<li>If we take F to be the set of all physical facts about the system, then all outputs are determined, and Ross's argument fails.</li>
<li>If we take F to be the set of known physical facts, then outputs are indeed undetermined, but this is only an epistemological issue. For a sufficiently detailed set of physical facts, the output <i>is</i> determined.</li>
</ul>
<li>Thus, all three of Ross's main arguments: quaddition, grue, and the problem of limited data, only point to a lack of knowledge about the system. </li>
<li>These epistemological concerns are not enough to draw the conclusion that the system is "physically and logically" indeterminate.</li>
</ul>
<br />
None of this addresses Professor Feser's point about the <i>meaning</i> of a physical process, which I will have to address (I hope!) another time.<br />
<br />
* I take Ross to mean "inequivalent" rather than "incompossible" here and throughout - see Richard's remarks in the <a href="http://somewhatabnormal.blogspot.com/2013/11/guest-post-purity-of-form-and-function.html" target="_blank">previous post</a>.<br />
Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com0tag:blogger.com,1999:blog-7164603649660539619.post-53283002330475464392013-11-23T10:47:00.000-05:002013-11-23T10:47:58.867-05:00Guest Post: Purity of Form and Function<i>While I'm gearing up for my assault on Mount Kripke, here's a guest post from Richard Wein.</i><br />
<br />
Hi everyone. Robert's invited me to make a guest post on the subject of James Ross's paper <a href="http://www3.nd.edu/~afreddos/courses/43151/ross-immateriality.pdf" target="_blank">"Immaterial Aspects of Thought"</a>. The resulting post is rather long, partly because there's a lot of linguistic confusion to be cleared up. I hope I can dispel a little of that confusion.<br /><br />At the core of Ross's argument is his insistence that our logical thinking must involve "pure forms". He then argues that physical processes can't have such forms, and so logical thinking must involve more than just physical processes. I see no good reason to accept that we need any such forms.<br /><br />Ross's concept of "pure forms" is hardly explained, and remains mysterious to me. He says, for example, that squaring involves thinking in the form "N X N = N^2". He doesn't seem to mean that we must think such words to ourselves. He seems to have in mind some unseen form, possibly Platonistic. In Section III, he talks briefly about "Platonistic definitions", and perhaps this example is one such.<br /><br />It may help here if I briefly give my own physicalist view, so that I can consider Ross's in contrast to it. I say that the only verbal forms that exist are the sorts that we observe, such as those in writing, speech and conscious thought. These observed verbal forms are produced by non-conscious, non-verbal physical cognitive processes. Of course there's a lot more to be said about how this happens, and particularly about consciousness, but these are not issues that Ross raises. He is not, for example, making an argument from consciousness. Nor is he making an inference to the best explanation, where we must consider the relative merits of his explanation and a physicalist one. He is making a purely eliminative argument, and so the onus is on him to eliminate physicalist alternatives, not on me to elaborate on them.<br /><br />The claim that our thinking must take the form of definitions in this sense seems to lead to a problem of infinite regress. If squaring is defined in terms of a more basic operation, multiplying, then how is multiplying defined? And so on. But I won't dwell on this point, because Ross's "pure forms" are so mysterious that I doubt I could make any specific positive criticism stick. My point is that we just don't need anything of the sort Ross is insisting on. He gives us no reason to think that the sorts of physical processes I've mentioned are incapable of producing everything that we actually observe. I don't think he even tries to show that. His only response to views like mine seems to be that, on such views, the actual processes we currently call "squaring" wouldn't be "real" squaring, but only "simulated" squaring.<br /><br />This response is a confused use of language, mistaking an empty verbal distinction for a substantive one. First, regardless of whether we call such operations "real" or "simulated", if they're sufficient to deliver everything we actually observe--and Ross doesn't seem to argue the contrary--then there's no reason to think we need anything more. That in itself should suggest some confusion on Ross's part.<br /><br />The distinction Ross was originally making was between processes that involve "pure forms" and those that don't. If the distinction he's now making between "real" and "simulated" processes is just a translation of the original distinction into different words, then the translation achieves nothing. He's just re-asserting his unsupported claim that we need such pure forms, but doing it in confusing new words. If, on the other hand, the new distinction were genuinely different from the original one, Ross would actually have to demonstrate that denying pure forms entails denying real squaring. He would have to make a substantive argument, and he wouldn't be able to do that without clarifying the meaning of his new distinction. In fact he makes no such argument (or clarification). He simply puts the words "we only simulate" into the mouth of the denier, as if it's indisputable that denying pure forms entails denying real squaring. So it's pretty clear that this is just a confusing terminological switch, masquerading as a substantive argument. The appearance of having achieved something arises through conflation of a weaker sense of the words (in which they are just a translation of the original claim) with a stronger sense (which has the appearance of a more irresistible claim). To accept Ross's conclusion on this basis is to commit a fallacy of equivocation.<br /><br />Unlike Ross's denier, I don't say that we don't "really" square. Neither do I say that we do "really" square. The word "really" is misleading here. If denying that we "really" square is to be taken as just another way of saying that we don't think in "pure forms", then I prefer to say--more directly--that we don't think in pure forms.<br /><br />There ends my main response to Ross's argument. But I'd likely briefly to address some other aspects of his paper which are liable to cause confusion.<br /><br />Ross uses the term "pure forms" interchangeably with "pure functions", and I'm afraid this translation may have led to a conflation of these concepts of his own with the concept of a mathematical function in the ordinary sense of that term. Mathematical functions are purely abstract, and don't exist in anything like the sense that physical objects do. Pairs of mathematical functions like addition and quaddition are correctly called "non-equivalent". To call them "incompossible" would be a kind of category error, mistakenly implying that it makes any sense to ask whether they can co-exist. Ross's talk of incompossible pure forms/functions is further support for the conclusion that he sees these as having a more real sort of existence than do mathematical functions (in the ordinary sense).<br /><br />I have no idea what it could mean for the process of squaring to take the form of a mathematical function. The messy, fallible real-world processes that we call "squaring" are quite a different thing from the abstract function that mathematicians call "f(x)=x^2". Talk of a process taking the form of a mathematical function seems to me like a category error, an attempt to transfer properties inappropriately between pure abstractions and real processes. Of course, during the process of performing an arithmetic operation, some definition of a function (some form of words) might be produced, e.g. in conscious thought. But that's a production of the process, and not the process itself or the form of the process. Moreover, simple arithmetic doesn't always involve giving ourselves any definitions, rules or instructions for how to proceed. The answers can come to mind (or speech) as the result of non-verbal non-conscious processes, without any verbal reasoning. That's why there's no infinite regress of definitions, rules or instructions.<br /><br />You may have noticed that I haven't mentioned determinacy. Ross's argument is primarily made in terms of pure forms. But at times he translates into the language of determinacy, and his summary argument is expressed in such language. This translation into the language of determinacy serves no useful purpose, but creates further opportunities for confusion, because Ross's "indeterminacy" is easily conflated with other senses of the word, and Ross himself encourages such conflation by appealing to work on other sorts of indeterminacy (and even "underdetermination") which have little to do with his argument.<br /><br />Since I don't think we need any "realization" of "pure forms", and I would question whether the the concept is even coherent, there's no point in my addressing Section II of the paper in detail. But I think it would be useful briefly to give a clearer account of the addition/quaddition scenario and "indeterminacy". Ross employs a variant of Kripke's quaddition function, where the differentiating point (instead of 57) is set to a number of years greater than the lifetime of the universe. That example seems peculiar to me, as I can see no reason why a system can't calculate a number of years greater than that lifetime. So I'll take a slightly different example of my own. Let the differentiating point be a number greater than any that can be represented by a given calculator. Then there's a sense in which the calculator equally well "realizes" addition and quaddition. That sense is that the calculator gives the answers for quaddition as well as it gives them for addition. As long as we don't confuse ourselves with talk of "pure forms", there's nothing remarkable about this. Ross wants to say that the calculator can't realize two different functions, so it must realize neither. But in the sense of "realize" that I've just used, there's no problem with saying that it realizes both, and the fact that it realizes both has no substantive significance.<br /><br />Given that we're not talking about epistemological or quantum indeterminacy, any indeterminacy lies just in the fact that often our categories are not sufficiently well-defined for us to be able to assign a given state of affairs to a single category. For example, for some people there is no fact of the matter as to whether they are best described as children or adults. That's just a limitation of language. Indeterminacy is significant for our understanding of how language works, and for making sure we use language in ways that don't cause confusion, but it doesn't have any substantive, non-linguistic significance. Some people are reading far too much into indeterminacy.<br />Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com8tag:blogger.com,1999:blog-7164603649660539619.post-35480813826310360062013-11-19T15:47:00.000-05:002013-11-19T15:47:48.511-05:00Grue Some MoreThe second point Ross brings up in support of the indeterminacy of the physical is <a href="http://en.wikipedia.org/wiki/New_riddle_of_induction" target="_blank">Goodman's Grue Argument</a>. This one is easily dealt with.<br />
<br />
Goodman defines something as "grue" if it is first observed before Jan1, 2025 (say) and is green, or is first observed after Jan 1, 2025 and is blue. He uses this to make a point about induction: any evidence we cite as evidence for the proposition "all emeralds are green" is also evidence for the proposition "all emeralds are grue." Thus, the grue problem casts doubt on the rationality of inductive conclusions.<br />
<br />
So we see that Goodman's point was about induction, not indeterminacy. But this is really unimportant for Ross's argument, because Ross doesn't actually <i>use</i> the grue argument in any essential way. Rather, he either cites grue as an example of the <a href="http://somewhatabnormal.blogspot.com/2013/11/a-pointless-point-about-data-points.html" target="_blank">problem of limited data</a>, or as an analogy to Kripke's quaddition argument. For instance, <a href="http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCwQFjAA&url=http%3A%2F%2Fwww.nd.edu%2F~afreddos%2Fcourses%2F43151%2Fross-immateriality.pdf&ei=iMlOUoPBEdTK4APqioCoBw&usg=AFQjCNFJii_QzooRqCxx0an_sZh2hin2WA&sig2=3g2p6M_iE7zttgawIex7Jw&bvm=bv.53537100,d.dmg" target="_blank">Ross writes</a>:<br />
<br />
<blockquote class="tr_bq">
A decisive reason why a physical process cannot be determinate among incompossible abstract functions is "amplified grueness": a physical process, however short or long, however few or many outputs, is compatible with counterfactually opposed predicates; even the entire cosmos is. Since such predicates can name functions from "input to output" for every change, any physical process is indeterminate among opposed functions. This is like the projection of a curve from a finite sample of points: any choice has an incompatible competitor.</blockquote>
But the problem of limited data, as we have seen, is irrelevant for the indeterminacy question. So the grue point devolves onto the Kripke/quaddition point, which I will consider next. Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com0tag:blogger.com,1999:blog-7164603649660539619.post-71656222024725334322013-11-15T12:59:00.000-05:002013-11-15T12:59:46.231-05:00A Pointless Point about Data PointsI've been, and continue to be, busy with my real work, so I have to apologize if these posts dribble out slowly, a bit at a time, rather than in one long, well-thought-out post the way Prof. Feser does. But maybe it will actually be an advantage to try to clear up one point at a time.<br />
<br />
Ross gives three main arguments to support his claim B: "No physical system is determinate." These are:<br />
<ol>
<li>Kripke's addition/quaddition argument.</li>
<li>Goodman's grue argument.</li>
<li>The problem of limited data.</li>
</ol>
Kripke is the central point of Ross's argument, and it is the most difficult to tackle. I'm going to start at the other end, with (3).<br />
<br />
The problem of limited data (PLD) is pretty easy to state. Suppose I have some system from which I can take data, and I am trying to determine what function the system is following in order to produce the data. If I take a limited number (say a finite number) of input-output pairs, there will be an <i>infinite</i> number of functions which fit the given data points. For example, suppose I have only three data points. Then there is exactly one quadratic function that will exactly fit those three points. But I could also fit the data with a cubic function, or a quartic function, or a polynomial of any higher degree, or an exponential function times an appropriate polynomial, etc.<br />
<br />
Now, how does this help Ross establish his (B)? Actually, it doesn't help at all. The mere fact that I have a limited amount of data doesn't tell me anything about the process that is producing that data. Since the PLD applies equally to determinate and indeterminate systems, it can't. This seems completely obvious to me, but since it seems to be a point of contention, I will spell it out.<br />
<br />
Suppose I get some set of N input-output pairs from a determinate process. (For Ross, this means having a human compute them.) Let someone else give me N input-output pairs from an indeterminate process that is simulating (in Ross's sense) the first process. (For Ross, this could be a computer.) Now, since Ross allows that the indeterminate process can simulate the determinate process very closely, the two data sets will be identical. (This is easy to see if we say the process in question is addition: the computer and the human will give the same outputs for the same inputs. Unless, of course, the human makes a mistake.)<br />
<br />
Since the N input-output pairs are identical whether I get them from a determinate or an indeterminate process, there is obviously no way I can tell <i>from the data</i> which sort of process produced that data.<br />
<br />
Now let's introduce the PLD. Clearly, it applies to <i>both</i> processes. So if (as Ross claims) the PLD provides support for the claim that the purely physical process is indeterminate, then it also provides support for the claim that the human-generated process is indeterminate. So the PLD strengthens Ross's case for B to the exact extent that it weakens his case for A (that humans are capable of determinate processes). In other words, it doesn't help him at all.<br />
<br />
This is what I meant when I wrote that Ross's arguments don't go beyond epistemology. The PLD says I can have only limited <i>knowledge</i> about the process that produced the data. But it says nothing at all about the metaphysical properties of that process.Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com2tag:blogger.com,1999:blog-7164603649660539619.post-44420131362319447732013-11-05T13:16:00.000-05:002013-11-05T13:16:11.045-05:00Goodbye, HildaI'd like to thank Prof. Feser for his continued patience in responding to my critique of Ross's argument. I've been very busy, but I finally had some time to look at his most recent response. He misconstrued the A, B, C, of my previous post (understandably, since I hadn't spelled them out clearly), and I began a long post carefully laying out the logic of my argument and why Feser's response didn't answer it. Then I realized that it <i>did</i> answer it, in spite of the misunderstanding about A, B, and C. The "purely physical" assumption is indeed the critical assumption in Ross's argument that I wasn't taking into account, and it does eliminate the Hilda objection in a non-question-begging way. I apologize to Prof. Feser for the unwarranted and unnecessary snark in my last post. I am hereby giving Hilda the boot. <br />
<br />
I hope to return to my original epistemological objection (as time permits), but I wanted to get this apology out in a timely manner.<br />
<br />
Crow is a dish best eaten warm.Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com16tag:blogger.com,1999:blog-7164603649660539619.post-82678976535662394922013-10-21T20:39:00.000-04:002013-10-21T20:39:24.066-04:00A Head ScratcherEd Feser has responded again, and it's a puzzler.<br />
<br />
I will ignore the first part of his post, in which he is once again arguing against some argument that is not the argument I made.<br />
<br />
Next, Feser points out that my objection, even if it worked against Ross, was irrelevant against Feser's own version of the argument.<br />
<blockquote class="tr_bq">
<span style="font-size: small;"><span style="line-height: 115%;">For another thing, it is not just <i>Ross’s</i>
views that are in question here, but <i>mine</i>. And I can assure Oerter that what <i>I </i>am claiming is (2) rather than
(1). So, even if what he had to say in
his latest post was relevant to the cogency of <i>Ross’s</i> version of the argument in question, it wouldn’t affect <i>my own</i> version of it.</span></span> </blockquote>
<br />
Well, I never said I was arguing against Feser's version of the argument, I explicitly stated I was critiquing Ross's argument. And that is what I will continue to do here, though I may return to Feser's version later if I have the time and inclination. <br />
<br />
Feser then goes on to explain why he thinks his version of the argument is actually what Ross intended anyway. Specifically, he addresses what Ross means by saying the calculator is not adding. Now, Ross makes a clear and consistent distinction in his paper between true adding, which he elaborates as carrying out the "pure function" of addition, and what the calculator does, which is only "simulating addition." This is a crucial distinction for him, because his basic claim is that humans can execute pure functions, while any purely physical system cannot.<br />
<br />
In my posts I have consistently (I hope) been using "adding" in Ross's first sense. I didn't think it was necessary to spell this out: since I was critiquing Ross's paper, I was using Ross's terminology, except where I explicitly stated otherwise. But to be clear, I will henceforth use ETPFOA ("executing the "pure function" of addition") instead of "adding."<br />
<br />
So when I said that Ross denied that the machine was adding, I meant it was not ETPFOA. Feser, on the other hand, wrote,<br />
<br />
<blockquote class="tr_bq">
<span style="font-size: small;"><span style="line-height: 115%;">Ross is not denying, for
example, that your pocket calculator is really adding rather than “quadding”....</span></span></blockquote>
<br />
So how does Feser respond? He quotes Ross's discussion of simulated addition, then writes:<br />
<br />
<blockquote class="tr_bq">
<span style="font-size: small;"><span style="line-height: 115%;">So, Ross plainly <i>does</i> say that there <i>is</i> a sense in which the machine adds -- a sense that involves
simulation, analogy, something that is “adding” in the way that what a puppet
does is “walking.” How can that be given
what he says in the passage Oerter quotes?
The answer is obvious: The machine “adds” <i>relative to the intentions of the designers and users, </i>just as a
puppet “walks” relative to the motions of the puppeteer. The puppet has no
power to walk on its own and the machine has no power to do adding (as opposed
to “quadding,” say) on its own. But
something from outside the system -- the puppeteer in the one case, the
designers and users in the other -- are also part of the larger context, and
taken together with the physical properties of the system result in “walking”
or “adding” <i>of a sort</i>. </span></span></blockquote>
<br />
<blockquote class="tr_bq">
<span style="font-size: small;">
</span>
<br />
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">In short,
Ross says just what I said he says.</span></span></div>
</blockquote>
<br />
<br />
Now it is very strange for Feser, who is a professional philosopher, to sweep aside an crucial distinction like this, as if it were unimportant. It is <i>not</i> true that Ross says the machine can add in the ETPFOA sense that both Ross and I are using. It <i>is</i> true that Ross says the machine can do something like adding - but only something that has the <i>name</i> of adding, and gets that name by analogy to ETPFOA, not because it is actually ETPFOAing.<br />
<br />
Moreover, I don't see anywhere Ross says that the machine "adds relative to the intentions of the designers and users," as Feser claims. And what exactly is Feser claiming here? That the machine ETPFOAs relative to the intentions of the designers? Or that it only simulates adding relative them? OK, the machine taken together with the larger context results in addition "of a sort" - but of <i>which</i> sort? Again, Feser glosses over the crucial distinction.<br />
<br />
You wouldn't think it possible, but there's actually worse to come. Quoting Feser again:<br />
<br />
<blockquote class="tr_bq">
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">Oerter
insists that I am misunderstanding Ross here.
As we will see in a moment, I am not misunderstanding him at all, but it
is important to emphasize that even if I were, that would be completely
irrelevant to the question of whether the argument for the immateriality of the
intellect that we are debating is sound.
For one thing, and quite obviously, whether or not I have gotten Ross
right on some exegetical matter is irrelevant to whether premises (A) and (B) of
the argument in question are true, and whether the conclusion (C) follows from
them. So Oerter is, whether he realizes
it or not, just changing the subject. </span></span></div>
</blockquote>
<span style="font-size: x-small;"></span> <br />
<br />
Later on, he continues in a similar vein:<br />
<blockquote class="tr_bq">
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">Evidently
the
reason Oerter thinks all this is worth spilling pixels over is that he
thinks his “Hilda” example shows that Ross is being inconsistent, and he
needs
for me to have gotten Ross wrong in order to make his “Hilda” example
work. I have already explained, in my
previous post, why Ross is not at all being inconsistent. But even if
he were, it wouldn’t matter. The alleged inconsistency, you’ll recall,
is
that Ross treats Hilda as adding despite the fact that we can’t tell
from her
physical properties alone whether she is, whereas he does not treat the
machine
as adding despite the fact that we can’t tell from its physical
properties
alone whether it is. Suppose he really
were inconsistent in this way. How does
that show that premise (B) of his argument is false (much less that (A)
is
false, or that the conclusion doesn’t follow)?
</span></span></div>
</blockquote>
<br />
<blockquote class="tr_bq">
<span style="font-size: small;">
</span><br />
<span style="font-size: small;">
</span>
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">Answer: It
doesn’t. The most such an inconsistency would
show is that Ross needs to clarify what is going on with Hilda that isn’t going
on with the machine. And there are
several ways he can do this consistent with the argument. First, he could say what I would say (and
what, as I have shown, <i>he does</i> in
fact say himself, despite what Oerter thinks) -- namely that the machine <i>does</i> add in a sense, but just not by virtue
of its physical properties alone. There
is perfect consistency here -- both systems, Hilda and the machine, add (albeit
in analogous senses), but neither does so in virtue of its physical properties alone.</span></span></div>
</blockquote>
<br />
This is just bizarre. Ed Feser, who revels in pointing out inconsistencies of the naturalists, is arguing that an inconsistency doesn't matter? Nor is this some trivial point of Rossian exegesis, as Feser implies: it's a basic contradiction in Ross's whole scheme.As I pointed out already, the distinction between ETPFOA and simulated adding is crucial to Ross's argument.<br />
<br />
The logic of my Hilda example is straightforward. Ross says that humans can ETPFOA. Ross says that A, B, and C entail that a computer cannot ETPFOA. I claim that A, B, and C are true for Hilda, too. So A, B, and C entail that Hilda cannot ETPFOA.<br />
<br />
With this contradiction, the whole argument falls to pieces. Now, you can argue that I am wrong: that A, B, and C are <i>not</i> true of Hilda. Or you can argue that there is some D that I missed that is true of the computer but not true of Hilda. But you can't say this example is <i>irrelevant</i> to the soundness of Ross's argument.<br />
Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com38tag:blogger.com,1999:blog-7164603649660539619.post-4835836046415249522013-10-19T02:50:00.002-04:002013-10-19T02:50:53.347-04:00What Does Ross Say?Well, no, I'm not making the sort of trivial, "silly" argument that Feser likes to ascribe to me. But before I can clarify this, it is necessary to clarify just what it is that Ross is saying. <br />
<br />
<a href="http://edwardfeser.blogspot.com/2013/10/oerter-on-indeterminacy-and-unknown.html" target="_blank">Feser writes</a>:<br />
<br />
<blockquote class="tr_bq">
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">Part of the
problem here might be that Oerter is not carefully distinguishing the following
two claims:</span></span></div>
<span style="font-size: small;">
</span><br />
<span style="font-size: small;">
</span>
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">(1) There
just is no fact of the matter, period, about what function a system is
computing.</span></span></div>
<span style="font-size: small;">
</span><br />
<span style="font-size: small;">
</span>
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">(2) The physical
properties of a system by themselves don’t suffice to determine what function
it is computing.</span></span></div>
<span style="font-size: small;">
</span><br />
<span style="font-size: small;">
</span>
<div class="MsoNormal">
<span style="font-size: small;"><span style="line-height: 115%;">Oerter
sometimes writes as if what Ross is claiming is (1), but that is not
correct. Ross is not denying, for
example, that your pocket calculator is really adding rather than “quadding”
(to allude to Kripke’s example). He is
saying <i>that the physical facts about the
machine by themselves</i> do not suffice to determine this. Something more is needed (in this case, the
intentions of the designers and users of the calculator). </span></span></div>
</blockquote>
<br />
<br />
What exactly <i>does</i> Ross claim? Here is Ross from <a href="http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCwQFjAA&url=http%3A%2F%2Fwww.nd.edu%2F~afreddos%2Fcourses%2F43151%2Fross-immateriality.pdf&ei=iMlOUoPBEdTK4APqioCoBw&usg=AFQjCNFJii_QzooRqCxx0an_sZh2hin2WA&sig2=3g2p6M_iE7zttgawIex7Jw&bvm=bv.53537100,d.dmg" target="_blank">his paper</a>:<br />
<br />
<blockquote class="tr_bq">
Adding is not a sequence of outputs; it is summing; whereas if the process were<br />
quadding, all its outputs would be quadditions, whether or not they differed in quantity from additions (before a differentiating point shows up to make the outputs diverge from sums). </blockquote>
<br />
<blockquote class="tr_bq">
For any outputs to be sums, the machine has to add. But the indeterminacy among incompossible functions is to be found in each single case, and therefore in every case. Thus, the machine never adds.</blockquote>
<br />
<blockquote class="tr_bq">
Extending the outputs, even to infinity, is unavailing. If the machine is not really adding in the single case, no matter how many actual outputs seem "right," say, for all even numbers taken pairwise (see the qualifying comments in notes 7 and 10 about incoherent totalities), had all relevant cases been included, there would have been nonsums. <b>Kripke drew a skeptical conclusion from such facts, that it is indeterminate which function the machine satisfies, and thus "there is no fact of the matter" as to whether it adds or not. He ought to conclude, instead, that it is <u>not</u> adding;</b> that if it is indeterminate (physically and logically, not just epistemically) which function is realized among incompossible functions, none of them is. That follows from the logical requirement, for each such function, that any realization of it must be of it and not of an incompossible one. [emphasis added]</blockquote>
Ross is quite clear: he is not saying (2) at all. Neither is he saying (1). He is saying something stronger than either (1) or (2): the machine does not add - period. It is not that the physical properties of the system alone don't determine what function it is computing, the system isn't actually computing any function at all. "... if it is indeterminate (physically and logically, not just
epistemically) which function is realized among incompossible functions,
<b>none of them is</b>."<br />
<br />
I just don't see how Feser can write "<span style="font-size: small;"><span style="line-height: 115%;">Ross is not denying, for
example, that your pocket calculator is really adding rather than “quadding”..." for that is exactly what Ross <i>is</i> denying. </span></span><br />
<br />
<span style="font-size: small;"><span style="line-height: 115%;">It is this denial I had in mind when I said Ross couldn't apply the same reasoning to Hilda without denying that Hilda adds, too. But rather than re-visit that argument I will wait for the professor to (I hope) clarify. </span></span> Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com5tag:blogger.com,1999:blog-7164603649660539619.post-33718573042814229212013-10-15T14:29:00.000-04:002013-10-15T14:30:09.428-04:00Feser and Ross and me<a href="http://edwardfeser.blogspot.com/2013/10/oerter-and-indeterminacy-of-physical.html" target="_blank">Ed Feser has responded</a> to <a href="http://somewhatabnormal.blogspot.com/2013/10/against-physicalism.html" target="_blank">my complaints about Ross's argument</a> - sort of. Once again, I am flattered that Feser thinks my amateur philosophizing worthy of his attention. I always learn a lot from our exchanges, even if I am not ultimately convinced of his point. He (correctly) diagnoses my confusion between indeterminacy of meaning and physical indeterminism. But that confusion doesn't (I think) invalidate my main point: that Ross's argument never gets him beyond epistemological indeterminacy.<br />
<br />
Oddly, Feser doesn't specifically respond to my critcism. Instead, he refers back to his American Catholic Philosophical Quarterly article. But in that article, he doesn't specifically respond to the epistemology objection, either. Here's what he wrote:<br />
<br />
<br />
<blockquote class="tr_bq">
Dillard also suggests that Kripke’s point is epistemological rather than metaphysical—that his argument shows at most only that the claim that someone is thinking in accordance with a certain function (such as addition) is underdetermined by the physical evidence, and not that the physical facts are themselves indeterminate. This is odd given that both Kripke and Ross explicitly insist that the points they are respectively making are metaphysical rather than merely epistemological. Indeed, Kripke says that “not even what an omniscient God would know . . . could establish whether I meant plus or quus,” because for the reasons given above, everything about my past behavior, sensations, and the like is compatible (not just compatible as far as we know, but compatible full stop) with my meaning either plus or quus. Nor does Dillard say anything to show otherwise.</blockquote>
That is, Feser merely states that Ross <i>says</i> that his point is metaphysical, not epistemological. But Feser doesn't give any additional reasons for us to believe that Ross has actually <i>established</i> this. Well, I agree that Ross says that - but I don't think he has established it.<br />
<br />
Here's why. Note that Ross's argument is just as valid when talking about what <i>another person</i> is doing when (say) adding. That is, when I am trying to determine whether Hilda is actually adding, or merely simulating adding, all I can do is investigate her physical actions and responses. If Ross's argument is correct, then from a finite amount of data such as these I cannot determine whether Hilda is adding or not. So (if Ross is right) I can never know whether another person is capable of addition.<br />
<br />
But note that from the above it doesn't follow that Hilda is <i>not</i> adding. It may be that Hilda is in fact doing something perfectly determinate. I just can't know whether she is or not. So it is clear that Ross's argument doesn't get us past the epistemological.<br />
<br />
This point ties in with my <a href="http://somewhatabnormal.blogspot.com/2013/10/rosss-double-standard.html" target="_blank">second complaint about Ross</a>: the double standard. If I can't say for sure that another person is not adding, then by the same token I cannot say for sure that a machine is not adding.* <br />
<br />
In his article, Feser almost makes the same point. Kripke's original point (if I understand it correctly) was, not only can I not be sure what someone else means when they say something, I cannot even be sure what I mean when I say something. That is, even my own thoughts are indeterminate in meaning. Ross obviously doesn't want this conclusion - his own argument relies on one's own thoughts being determinate. Feser points out that (using Frege's conception of meaning) we cannot infer from the external indeterminacy that there is no internal meaning. He writes:<br />
<br />
<blockquote class="tr_bq">
Frege emphasized that the sense of an expression is not a private psychological entity such as a sensation or mental image, any more than it is something material. Thus he would hardly take an argument to the effect that meaning cannot be fixed either by sensations and mental images or by bodily behavior to establish that there is no determinate meaning at all.</blockquote>
<br />
But establishing that there is "no determinate meaning at all" is precisely what Ross needs for his argument. So the argument fails. <br />
<br />
*<span style="font-size: x-small;"> Though it is not directly relevant to the argument, I want to point out that the situation is actually <i>worse</i> with respect to the machine than it is with respect to another person. We can open up the machine, trace its circuits or it mechanism or whatever, and deduce what it will do for a given input. With another person, we can only investigate the physical outputs: we can't open up Hilda's brain and trace its circuitry. Well, not yet, at any rate. </span>Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com15tag:blogger.com,1999:blog-7164603649660539619.post-13582326890922541752013-10-12T06:55:00.000-04:002013-10-12T06:55:12.331-04:00Ross's Double StandardAnother problem with <a href="http://somewhatabnormal.blogspot.com/2013/10/against-physicalism.html" target="_blank">Ross's argument</a> is the double standard he employs. It's obvious that humans are not nearly as accurate as machines when it comes to computations. But Ross doesn't take this as evidence that humans are not carrying out a pure function. On the contrary, he suggests that mistakes could be evidence that the human <i>is</i> carrying out the function. <a href="http://www3.nd.edu/~afreddos/courses/43151/ross-immateriality.pdf" target="_blank">He writes</a>:<br />
<br />
<blockquote class="tr_bq">
This is not a claim about how many states we can be in. This is a claim about the ability exercised in a single case, the ability to think in a form that is sum-giving for every sum, a definite thought form distinct from every other. When a person has acquired such an ability is not always transparent from successful answers, and<b> it can be exhibited even by mistakes. </b>[Emphasis added.]</blockquote>
<br />
<br />
But when he talks about machine addition, he counts any error, even a potential error many years
in the future, as evidence that the machine doesn't truly add.<br />
<br />
This is a blatant double standard. Logically, if a mistake is evidence that X is not performing the function, then that is true whether X is a human or a machine.<br />
<br />
<br /><br />Robert Oerterhttp://www.blogger.com/profile/09708981993708509662noreply@blogger.com6