Tuesday, August 31, 2010

Naturalism, Materialism, Physicalism, Oh My!

This post is part of a series on naturalism. The first post is here.

I noted in that post Trent Dougherty's complaint that he couldn't find a decent defense of naturalism anywhere.

Has anyone given a decent academic case for naturalism? The closest I can recall is Melnyk's in his Material Manifesto. Maybe David Papineau's closure argument could be generalized. I think naturalists just assume it's all going to work out. It just seems utterly hopeless to me.

Despite Trent's complaints, I had little trouble finding serious philosophical defenses of naturalism. I am working my way through two of them: Physicalism, by Jeffrey Poland, and A Physicalist Manifesto, by Andrew Melnyk. Trent seems to have read the latter (though he got the title wrong), but gives no clue about what he found lacking in its presentation.

I am going to try to summarize the approaches taken by Poland and Melnyk. But first, why "physicalism" rather than "naturalism"?

According to the Stanford Encyclopedia of Philosophy, naturalism "has no very precise meaning in contemporary philosophy." It suggest a commitment to natural, as opposed to supernatural, entities and explanations. But, the SEP notes, "the great majority of contemporary philosophers would happily accept naturalism as just characterized," without necessarily accepting such ideas as being able to reduce mental phenomena to physical phenomena.

Materialism and physicalism are sometimes used synonymously. Materialism is sometimes taken to imply that only matter truly exists. Since Einstein discovered that E = mc^2 over 100 years ago, it is hard to believe that anyone would make this claim today. In contemporary understanding, matter and energy are interchangeable; they are, in fact, two aspects of the same thing. Thus, the materialist should at least expand the physical basis to include energy (or perhaps the energy-momentum tensor). Too, the term "materialism" has a variety of other uses, including Marxist and eliminative, which is perhaps why those writing about materialism in the current sense prefer the term "physicalism" (even though my spell checker doesn't think it's a word).

Physicalism, very roughly, is the idea that everything that exists is in some sense dependent on a physical substrate. But how to make this more precise? In what sense should higher-order phenomena (anything from a chair to the concept of justice in the mind of Antonin Scalia) depend on the purely physical facts about the world? Philosophers have proposed many different types of dependence.

  • Identity: Everything that exists can be identified with some subset of the physical world.
  • Definition: Everything that exists can be defined in the language of physics.
  • Derivation: The laws of the higher-order sciences can be derived from the laws of physics.
  • Supervenience: Any possible world that is physically indiscernible from the actual world is, in fact, completely indiscernible from the actual world.
While each of these captures some aspect of the physicalist thesis, Poland and Melnyk agree that none of them is completely satisfactory. Some are too strong: it seems highly unlikely that any purely physical system can be identical to the concept of justice in the mind of Antonin Scalia. Others are too weak: the indiscernibility requirement of supervenience can't guarantee that non-physical facts can be explained in terms of physical facts.

A better formulation, according to both authors, is given by realization physicalism: everything that exists is either physical, or is realized by a physical property or system.

That means we need to answer two questions. What does it mean for something to be physical? And what does it mean to be realized by something physical?

Next time: Physics is Fundamental!

Saturday, August 28, 2010

Trent Doesn't Get Naturalism

I just can't take naturalism seriously. That is, I can't take seriously any view that entails either the proposition that some contingent fact occurred for no reason or that in essentials, the universe (or world or nature or whatever you want to call it) couldn't have been relevantly different from the way it in fact is. And if I had to accept some set of contingent facts as brute, I'd be strictly guided by the number of types and tokens and parameters postulated by a theory. I also find implausible impersonal accounts of a necessary ground in some "natural" force or fact.
...the fact is I try extremely hard to take seriously all positions, especially rivals to my own views.... I read every academic book I can find defending atheism.... But when it comes to "Scientific Naturalism" in its many and varied forms, I draw a total blank. The Dennet/Dawkins/Hitchens/Harris stuff is a total loss. But there's not much better.
Trent's post really gave me a jolt. I've been an atheist for many years, primarily on the basis that there is simply no good evidence for a god of any sort, let alone the sort of god that Christians or other religious people propose. But if it's reasonable for atheists to ask theists to defend their worldview, then certainly turnabout is fair play: it's reasonable for theists to ask atheists to defend their worldview, too. But, surely, the picture can't be as grim for naturalism as Trent claims?

So I decided to look into it, both for my own benefit, to develop a more coherent personal worldview, and so that I can defend that worldview if I ever run into someone like Trent: intelligent, educated, highly sophisticated philosophically, and theist.

My intuitive understanding of naturalism was in terms of reductionism: all phenomena are, at root, physical phenomena. But there are phenomena we all experience that are not obviously reducible to physical phenomena: mental phenomena like ideas and perceptions. One need not be an atheist to think that mental phenomena are of a different order than physical phenomena. For instance, a Cartesian dualist might hold that there are embodied spirits, while denying the possibility of disembodied spirits.

On a naturalist account, mental phenomena reduce to brain phenomena, brain phenomena reduce to interactions among neurons, interactions among neurons reduce to biochemical processes, and biochemical processes reduce to physical processes among protons, neutrons, and electrons. But how is this reduction to be achieved? And what, if any, reason is there to accept this view as opposed to any other view?

Next time: Naturalism, Materialism, Physicalism, Oh My!

Thursday, August 26, 2010

Moral Anti-Realism

This post is part of a series on theories of ethics: first post, second post.

Moral anti-realists deny that moral values are mind-independent. We have already encountered one version of anti-realism: non-cognitivism, which claims that moral statements are not the sort of things that can be true or false, rather, they are ejaculations roughly equivalent to "Boo!" or "Yuck!"

The flip side of this is moral error theory, associated with J. L. Mackie. Error theory is a cognitivist theory - moral statement are capable of being true or false - but the error theorist claims that, in fact, no such statements are true, because they all reference things (moral values) that don't actually exist.

The moral error theorist stands to morality as the atheist stands to religion. (SEP)

Finally, there is ethical subjectivism, that holds that moral facts exist but are mind-dependent in some way: morality is about mental attitudes rather than about objective moral entities that exist "out there."  One version of subjectivism is moral relativism: moral truths are relative to the individual, or to the group to which the individual belongs. However, it is possible to be subjectivist without being relativist, and vice versa.

This completes the overview of the main approaches to ethics. I can't resist adding some comments of my own here.

There seems to be - in the sources I have looked at, at least - considerable tension between prescriptive approaches to ethics (how should one go about making moral decisions) and descriptive ones (how do people actually go about making moral decisions). Some ethical theories (utilitarianism, for example) are clearly intended prescriptively, while others (error theory) just as clearly are not. All these are lumped together under the label "metaethics." It seems to me that these ought to be two completely different disciplines.

On the descriptive side, I have been reading Moral Minds, by Harvard's Marc Hauser. His approach (and that of the researchers he cites) promises to be a game-changer in descriptive ethics. He describes numerous experiments in which people are presented with moral questions (e.g. the famous trolley problems) and must decide what actions are permissible, obligatory, or forbidden. He relates cases of people with various mental impairments and discusses how these illuminate models of moral decision-making. He argues for a Chomskian approach. We are born with some innate ability to learn language, but the specifics of the language we learn are shaped by the linguistic environment in which we grow up. So with morality: we are born with some innate moral capacities, but the specific morality we end up with is shaped by the cultural environment. Whether or not his view turns out to be fruitful, it seems certain that we will learn more about how moral decisions are actually made by way of experiments of this sort than by the armchair speculations of philosophers.

But where does this leave us as far as the prescriptive side of the issue? Does learning about how people make moral judgments help us decide how people ought to make moral judgments? It seems we have here a meta-version of Hume's is-ought problem: no amount of research on how moral judgments are made will tell us how they ought to be made.

Thursday, August 19, 2010

Naturalism self-destructs?

A claim frequently expounded by theists is that naturalism is self-defeating: the claims of naturalism, if true, would prevent anyone from ever knowing that they were true. Anthony Flew devotes a chapter of Atheistic Humanism to this claim.

He quotes J. B. S. Haldane:

I am not myself a materialist because if materialism is true, it seems to me that we cannot know that it is true. If my opinions are the result of chemical processes going on in my brain, they are determined by the laws of chemistry, not those of logic.

Flew says Haldane later repudiated this line of reasoning. Nonetheless, let's try to lay it out logically.

Naturalism is self-defeating, version 1 (NSD1):

  1. My opinions are either the result of chemical processes or logical processes.
  2. If naturalism is true, then my opinions are the result of chemical processes.
  3. Therefore, if naturalism is true, my opinions are not the result of logical processes.
The problem here (Flew points out) is with (1.). This is a false dichotomy: there is no reason to think that the result of chemical processes cannot also be the result of logical processes. It's like saying, "Why trust the output of that computer when you multiply two numbers with it? It's just the result of electronic processes, so it can't be the result of mathematical rules!" The mistake here is that the electronic circuits of the computer have been set up precisely so that they implement mathematical rules. There is no conflict between the physical description (electrons) and the logical description (multiplication).

Flew goes on to say that Popper gave a different version of Haldane's argument.

...if "scientific" determinism is true... we believe it,not because we freely judge the arguments or reasons in its favour to be sound, but because we happen to be so determined (so brainwashed) as to believe it....

Flew elaborates that the question has now become

...whether we could by any means have believed other than we did. Unless we could  we cannot take credit for having, as rational beings, judged that these beliefs are true.

Let's call this

Naturalism is self-defeating, version 2 (NSD2):

  1. If naturalism is true, the world is deterministic.
  2. If the world is deterministic, then our beliefs are determined by things outside our control.
  3. If our beliefs are determined by things outside our control, then we could not have believed otherwise than we did.
  4. If we could not have believed otherwise than we did, then our beliefs are not the result of a rational judgment.
  5. If  our beliefs - specifically, our belief in naturalism - are not the result of a rational judgment, then there is no rational reason to go on believing in naturalism.
The reader will notice that this is, essentially, a version of the Consequence Argument. The issue of naturalism has become an issue of free will.

Flew appears to accept this version of the argument:

...naturalism is in this way refuted in as much as such a naturalist can be taken, as surely he must be, to be claiming nothing more nor less than to know that his scientifically grounded naturalism is nothing more nor less than true.

I find this sentence confusing and cluttered, so let's redact the unneccessary verbiage:

...naturalism is in this way refuted in as much as such a naturalist can be taken to be claiming to know that his scientifically grounded naturalism is true.
In his Epilogue to the chapter, however, Flew clarifies that this is only the case if the words "explain naturalistically" are taken to mean an explaining away of the phenomena. For Flew, on the contrary,

...explanations of the physical aspects of the behavior of these organisms in terms of physical causes are not necessarily irreconcilable rivals to explanations of other aspects of that behavior in irreducibly different terms.
It seems to me, though, that Flew concedes too much. NSD2 fails on several counts. First of all, Premise (1.) is simply false: our best accounts of the fundamental workings of the physical universe are not deterministic. Secondly, even if Premise (1.) should somehow turn out to be true, the rest of the argument suffers from the same issues as the Consequence Argument - specifically, the fatalism fallacy.

So, I don't see any reason to accept either version of NSD.

Sunday, August 15, 2010

Moral Realism

Moral realism makes the claim that moral statements are about actual, objective facts about the world, and that some moral claims are in fact true, independent of what country or social group you are from.

For a realist, moral facts are as certain as mathematical facts.  ("Moral Realism," The Internet Encyclopedia of Philosophy)

If "Stealing is wrong" is a true statement, then stealing is wrong for all people at all times. It is not wrong for some people or some groups and OK for other people or other groups. This is in contrast to moral relativism, which claims that moral statements may be valid for some groups but not for others. 

The truth or falsity of moral judgments, or their justification, is not absolute or universal, but is relative to the traditions, convictions, or practices of a group of persons.

We can all agree that there are, in fact, many different and incompatible moral/ethical systems in the world ("descriptive moral relativism"). But most of us would like to think that there are some moral truths that are universally valid. "It is wrong to torture innocent children," for example. If we discovered a culture that tortures children for amusement, the relativist would find herself in a tight spot: if morals are relative to the culture, and this culture accepts torture of children, then on what basis can the relativist condemn this torture?

Moral realists insist that some things, like torturing children, are really, really wrong, independent of the culture or the individual's beliefs.

Some realists think that moral properties can be described in terms of some objective features of the natural world. This is called ethical naturalism. For instance, utilitarianism says that morality seeks the "greatest good for the greatest number of people." Assuming that the "greatest good" can somehow be quantified, this makes moral decisions reducible to calculations involving objective properties of the world.

For other realists, moral properties really exist but are irreducible properties. These are the non-naturalists. For instance, ethical intuitionists hold that humans have an intuitive grasp of right and wrong, and this intuition is not reducible to any natural features of the world (like pain and pleasure, for example).

Some other realist theories:
  • Certain theistic theories, such as natural law theory.
  • Deontological ethics: Right and wrong inhere in actions themselves, rather than in their consequences. For example, if killing is wrong, then killing Hitler is wrong, even if it would save millions of lives.
  • Virtue ethics: Doing right consists of striving for excellence in all of one's roles: as (possibly) a parent, as a worker, as a citizen.

Tuesday, August 10, 2010

Flew: Basic Limiting Principles

The recent passing of Anthony Flew led me to pull a book off my shelf that had sat there, unread, for some time: Atheistic Humanism. I had tried to read it some years ago, but hadn't found it compelling enough to continue. Reading it today, I still find myself wondering how someone who is saying things so obvious could become so famous. But, having experienced many Internet discussions in the meantime, some arguments seem to stand out enough to be worth repetition.

For instance: Flew (crediting a 1949 paper by C. D. Broad) calls attention to the "basic limiting principles" [which he abbreviated BLPs: I detest abbreviations, so will write it out instead]. These are more "familiar and more fundamental than any of the named laws of physics." An example (mine, not Flew's): an object, dropped from rest, falls toward the earth, not away from it. This is a matter of everyday experience, and one need not know General Relativity, or even Newton's inverse square law, to appreciate it. But here's Flew himself:

Suppose, for instance, that there has been yet another security leak in Washington.... Then everyone, or almost everyone, assumes that some hostile agent has had some form of direct or indirect sensory access to the top-secret material that is now secret no longer. It never seriously enters most people's heads that that material might have been telepathically or clairvoyantly read by an agent who at no time came within normal sensory range. That information can be acquired without the employment of the normal senses is thus precluded by a basic limiting principle.

Suppose, again, that there had actually been an explosion in the nuclear power station at Three Mile Island. No one, or almost no one, would have suggested that this might have been a case of sabotage by psychokinesis. 

Atheists (Flew notes) are often accused of naturalistic dogmatism. According to these critics, atheists choose a starting point that rules out the supernatural. Theists, being more open-minded, allow the possibility of supernatural explanation. But Flew responds:

Yet it is simply grotesque to complain, in the absence of any such decisive falsifying evidence, that these appeals to the basic limiting principles and the named laws of established physics are exercises in a priori dogmatism. For what "a priori" means is prior to and independent of experience. But in both these kinds of cases [i.e., the insider leak and the nuclear explosion quoted above] we have an enormous mass of experience supporting our present beliefs and our present incredulities.

If your car won't start, who do you take it to? The mechanic, on the assumption that there is a mechanical or electrical problem, or the priest, on the assumption that it is infested with demons and needs exorcism? Our actions prove that we - theists and atheists alike - make the naturalistic assumption all the time. It is an assumption based, not on dogma, but on a wealth of collective experience: the basic limiting principles.

Monday, August 9, 2010

I Never Metaethics I Didn't Like

One of the challenges atheists face from theists is on the foundations of ethics. Of course, theists themselves face problems on this score. But it is an important issue and worth some attention, in my opinion. I know next to nothing about the philosophical approaches to ethics, so I will begin with some very basic stuff: classifying the different approaches to ethics that are out there, a discipline known as metaethics

If you had asked me a couple of weeks ago, I would have guessed that the most fundamental distinction in metaethics is the one between moral realists and moral anti-realists. Realists hold that moral facts are mind-independent facts, objective properties about the real world. Anti-realists, on the contrary, think moral facts are subjective, or are matters of convention among a group of people.

There is, however, a still more fundamental distinction; between the (unhelpfully named) cognitivist and non-cognitivist approaches to ethics. Cognitivists hold that moral claims, say, "Eating meat is wrong," are propositions: statements that might be true or might be false, but about which it is meaningful to argue whether they are true or false. For some cognitivists (anti-realists), the truth or falsity might be a matter of subjective opinion or group convention; for others (realists), it might be a matter of objective fact. But for both, moral statements can be meaningfully given the labels "true" or "false," at least with respect to a person's beliefs.

Non-cognitivists, then, deny that moral claims can be true or false, or that they say anything about anyone's beliefs.  Rather, moral statements express opinions, or are prescriptive. On the former view (known as emotivism), "Eating meat is wrong" is simply a way of saying "I disapprove of eating meat - and you should, too!" Or, as it is sometimes put more briefly, "Boo on eating meat!" The prescriptivist view says something similar, but emphasizes the "you should, too!" part: moral statements are imperatives; commands that should be obeyed, not just by the speaker, but by everyone. Non-cognitivists are necessarily moral anti-realists.

Non-cognitivism is similar to some anti-realist cognitive accounts, as the Stanford Encyclopedia of Philosophy points out:

It is useful to contrast non-cognitivism with one particular variety of cognitivism in order to more clearly present what the non-cognitivist is claiming. Various versions of cognitivist subjectivism equate moral properties such as rightness with the property of being approved of by some person or group. To be right is to be approved of by the speaker, or the speaker and her friends, or the members of the speaker's society, or everybody...

But this by itself is not sufficient to make the position non-cognitivist. This variety of subjectivism agrees with one of the positive non-cognitivist theses (that moral utterances conventionally express non-cognitive attitudes), but it does not agree with either of the essential negative non-cognitivist claims (that the judgments don't express beliefs and/or that they are not truth-apt)....

A simple example gets the idea across. One can express dislike of something by saying that one dislikes it. This is the way that a cognitivist subjectivist thinks we express moral attitudes. But one can also express dislike of something by booing or hissing. This is much like the way some non-cognitivists think we express moral attitudes. The latter way of expressing an attitude is different from the way cognitivist subjectivists think we express moral attitudes because it expresses the attitude without saying that we have the attitude.

Thus, for the non-cognitivist,  moral statements are not claims about the beliefs or values of the speaker or of some group, they are merely speech acts that express approval, or disapproval, or that encourage conformity with some norm.

Problems arise for the non-cognitivist when simple moral statements are part of longer sentences. From the Wiki page:

  • Eating meat is not wrong.
  • Is eating meat wrong?
  • I think that eating meat is wrong.
  • Mike doesn't think that eating meat is wrong.
  • I once thought that eating meat was wrong.
  • She does not realize that eating meat is wrong.
Attempts to translate these sentences in an emotivist framework seem to fail (e.g. "She does not realize, 'Boo on eating meat!'"). Prescriptivist translations fare only slightly better ("She does not realize that she is not to eat meat").

This is called the embedding problem. It seems that, at least in the way they are normally used, moral claims express more than mere (dis)approval.