Monday, April 30, 2012

Blackford on Harris on Free Will

Russell Blackford has a very thoughtful review of Sam Harris's Free Will. Like Jerry Coyne, Sam thinks that free will means

  • - We can never act otherwise in the strong and mysterious sense, mainly because this is precluded by the fact, as he sees it, of causal determinism.
  • - We are not "the conscious source of most of our thoughts and actions in the present."
 But, Blackford says, this is neither what (many) philosophers mean by free will, nor is it what most people think of by that term. So Sam is attacking a straw man.

Update: See also the thread at Talking Philosophy.

(Fixed the original review link: thanks, Garren!)

Thursday, April 26, 2012

The Jesus Wars Continue...

Richard Carrier posts a scathing and almost unbelievably vitriolic review of Bart Ehrman's book on his (Carrier's) blog. (I don't see much of an academic future for this lad if this is how he deals with critics....) Ehrman responds on his own blog.

Tempting though it is to try to score this fight, I'm going to pass, and instead comment on a paper by philosopher Stephen Law that also addresses the existence question. (There's a shorter version at Secular Outpost.) The core idea is this premise:

(P2) Where testimony/documents weave together a narrative that combines mundane claims with a significant proportion of extraordinary claims, and there is good reason to be sceptical about those extraordinary claims, then there is good reason to be sceptical about the mundane claims, at least until we possess good independent evidence of their truth.

He concludes that

The contamination principle, P2, is a prima facie plausible principle that, in conjunction with other prima face plausible premises, delivers the conclusion that, in the absence of good independent evidence for the existence of an historical Jesus, we are justified in remaining sceptical about the existence of such a person.

Now, if Law were simply saying that we should be initially sceptical, before a detailed historical investigation, of any and all claims about Jesus that we find in the New Testament, then he is not saying anything new. NT scholars have subscribed to this view for many decades, and any competent scholar knows that they must fight strenuously for any statement to be taken as more or less accurate reflection of something Jesus actually said. (See, for example, J.D. Crossan's book The Historical Jesus to find out how this is done.)

But this is not what Law is saying. Rather, he thinks that, even after a detailed historical investigation, the very nature of the evidence means that no reliable conclusion can be obtained. He specifically considers the usual criteria that NT scholars use to evaluate individual sayings and acts, and declares them insufficient to establish a conclusion, even about basic facts like whether Jesus lived.

Not, mind you, that he has carried out such a detailed investigation and come to a negative conclusion. No, he claims that regardless of what comes out of a detailed investigation, the philosophical principles he lays out preclude a positive result.

In effect, he is saying that philosophy trumps history. This bothers me, in part because I have recently been involved in a discussion over on Victor Reppert's blog where some folks are claiming that philosophy trumps science.

But let's return to Law's "contamination principle" (P2). As many folks have pointed out, most ancient sources from the time of Jesus have supernatural episodes interlarded with portions that are generally agreed by historians to be reliable history. If we are not to reject all such sources, we must set some kind of a cut-off point: 25% miracles, dump the whole thing; 24% miracles, OK to use it. Or whatever.

Now, suppose we have a document that contains 30% miracle stories. By Law's criterion, we should dump it. But suppose that detailed historical investigation reveals that this document is actually a composite document, written by two different people at two different times. (And possibly combined into a single document by a third person, or one of the two original authors: I don't think the details matter.) And suppose that one of the source documents doesn't contain any miracles at all, while the other source contains a high percentage.

Now we have a contradiction: the contamination principle demands that we dump the document as a whole, but it allows us to retain the source document.

So it seems to me that Law's P2 cannot do what he wants it to do. It cannot circumvent the detailed historical investigation and declare it invalid. A detailed confrontation with the actual historical evidence is the only way to derive valid historical conclusions.

And that's what historians (and NT scholars) do.

Tuesday, April 24, 2012

The Consequence Argument

(This is a repeat post. Originally posted on April 19, 2010, it was inadvertently deleted from the archive.)

In my previous post on free will, I mentioned the "Consequence Argument": 

The Consequence Argument 

  1. No one has power over the facts of the past and the laws of nature. 
  2. No one has power over the fact that the facts of the past and the laws of nature entail every fact of the future (i.e., determinism is true). 
  3. Therefore, no one has power over the facts of the future. 
  4. If determinism is true, it appears that no person has any power to alter how her own future will unfold, and therefore no moral responsibility for it. 
I proposed that the argument is unsound because Premise #2 is false: because of quantum mechanics, determinism is false.

This line of argument might leave one with an unpleasant feeling that the root of the matter has somehow been bypassed. Let's suppose that the future is not completely determined by the facts of the past and the laws of nature: rather, the future is determined by the facts of the past and the laws of nature and some sequence of random quantum events. How does this help?

 In fact, it doesn't seem to help at all. The future is just as determined, from our point of view. We have no more control over the outcome of random quantum events than we have over deterministic physical processes.

So it seems that the whole issue of determinism might have been a mere distraction. The real root of the matter lies deeper.

To get at that root, let's try to break down the consequence argument. We start with the idea that my actions are the result of my mental state. My mental state is the result of the processes of my brain, and my brain is a biological organ. My brain consists of neurons that function according to the laws of biochemistry, and those laws are ultimately reducible to physical processes between elementary particles like neutrons, protons, and electrons.

 This is just straightforward reductionism. I assume that there is no magic going on at any stage of the process: there is no immaterial spirit or soul that intervenes at some level to change the laws of nature.

When we apply the reductionism microscope, we end up with a feeling that can be summed up as "It's all just electrons." If everything I say and do is determined by what those electrons do, there doesn't seem to be any room for me and my decisions.

There is a feeling, then, that the future is fixed by the past and the laws of nature, regardless of whether the laws of nature are deterministic or indeterministic. Certainly there is nothing I can do do affect the paths of those electrons, regardless of whether they obey quantum mechanical laws or some other sort of laws. And barring, of course, any sort of magical soul force that can divert the electrons from their physically established paths.

So things are looking bleak for free will, on any naturalistic account. However, it may be that the uncomfortable feeling that "the future is fixed" is not, in fact, anything we should be worried about. Under any account of the world, we can imagine the past, present, and future laid out before us as a four-dimensional image: a God-like perspective (as Daniel Dennett suggests in Elbow Room , p. 101-102). On any account, there is only one future. (Here I am leaving aside many-worlds interpretations of quantum mechanics.) So from this perspective, the future is fixed, and nothing can change it. But surely this is not what we worry about when we question whether we have free will! No matter how much free will we have or don't have, there is still only one future in store for us.

There is actually a fallacy hidden in the idea that "the future is fixed," one that is sorted out in a wonderful article by Norman Swartz. This is the fallacy of "logical fatalism": that because something does occur, it must occur. Swartz writes,

Logical fatalism confuses the semantic (truth-making) order. It makes it appear that the truth of a proposition 'causes' an event to occur. It is, rather, that the event's occurring tomorrow 'makes' (but does not cause) the proposition to be true today. 

So the idea that the future is fixed shouldn't cause any discomfort.

Next time: some very uninteresting questions about free will.

Sunday, April 15, 2012

More Free Will Than You Really Need

Since I've been busy, and the free will issue is hot right now, here's a repeat post from my free will series:

(Originally posted April 3, 2010)

Free will and quantum mechanics

I never used to spend much time thinking about the problem of free will. If I can think, "I'm going to move my hand now," and then move my hand - well, that seems like enough free will for me.

Recently, though, I started reading up on the free will debate. Here are two of the arguments philosophers use. (The first argument is courtesy of the Stanford Encyclopedia of Philosophy, the second is cribbed from Norman Swartz.)

Argument #1 – There is No Moral Responsibility if Determinism is True

Premise 1. No one has power over the facts of the past and the laws of nature.
Premise 2. No one has power over the fact that the facts of the past and the laws of nature entail every fact of the future (i.e., determinism is true).
Premise 3. Therefore, no one has power over the facts of the future.
Thus: If determinism is true, it appears that no person has any power to alter how her own future will unfold, and therefore no moral responsibility for it.

Argument #2 - Causal Determinism is a Necessary Condition
for Moral Responsibility
Premise 1: Unless there are extenuating circumstances, persons are (to be) held morally responsible for their actions.
Premise 2: Being unable reasonably to have foreseen the consequences of their actions is one such extenuating circumstance. (Recall that young children who cannot reasonably foresee the consequences of their actions are not to be held morally responsible for the consequences.)
Premise 3: In order to be able to anticipate or foresee the likely (or even the remotely likely) consequences of one's actions, the world must not be random, i.e. the world must be fairly regular (or causally determined).

Thus: Moral responsibility requires that there be causal determinism.

So the first argument (known as the consequence argument) seems to show that if the universe is deterministic, then there is no free will (because everything in the future is determined by events that happened long ago), and hence no moral responsibility. But the second argument (I don't know if it has a name) says that if there is no determinism, then there can't be any moral responsibility, either. Taken together, the two seem to imply that there can be no moral responsibility. I don't think this conclusion is correct, and neither does Swartz. You can read his notes to see how he resolves the problem; here, I want to consider a different aspect.

The current best models of how the universe works are based on quantum mechanics, and quantum mechanics is not deterministic. Or perhaps I should say quantum mechanics is partially indeterministic. That is, the quantum state of a closed system determines the quantum state of the system at a later time,  but the quantum state of the system doesn't determine all of the interesting aspects of the system. In fact, for any quantum system, there will always be questions I can ask about the system that don't have a definite answer - even if the quantum state of the system is exactly known. However, quantum mechanics can give us the probabilities of the various possible answers to any question, and so the future is partially determined: determined up to the range of possible values allowed by quantum mechanics.

How does quantum mechanics relate to the two arguments outlined above? The consequence argument is right out: Premise 2 is simply false if quantum mechanics gives a true picture of the world. What about Argument #2? According to Premise 3 of this argument, the world must be "fairly regular," which, according to quantum mechanics, it is. But the indeterminacy of quantum mechanics provides some elbow room (in Daniel Dennett's phrase), so that the future is not completely determined by the past. Quantum mechanics thus seems to walk a fine line between a clockwork universe in which every action of every person is, in principle, completely predictable, and a chaotically random universe in which nothing is predictable and so there can be no moral responsibility.

Quantum mechanics may not be the explanation of free will, but it does seem to allow for free will.

Monday, April 2, 2012

Free Will Rides Again

The blogosphere has been full of free will discussions once again. Julian Baggini reviewed several recent books, including Sam Harris's Free Will. The Chronicle of Higher Education ran a series of short articles on free will: start here and follow the links on the page for the others. As if that weren't already a feast, Russell Blackford has been reviewing each of the CHE articles on Talking Philosophy.

And last, Jerry Coyne responds to Blackford's critique on his blog. There's some good discussion in the comments, about evenly split between eliminativists and compatibilists.