Wednesday, November 9, 2011

48 arguments against naturalism

Consider this argument:

  1. A desire to be morally perfect is morally required for humans.
  2. If naturalism is correct, a desire to be morally perfect cannot be fulfilled for humans.
  3. If a desire cannot be fulfilled for humans, it is not morally required for humans.
  4. Therefore, naturalism is not correct.
This argument provides a schema for a family of arguments. One obtains different members of the family by replacing or disambiguating the underlined terms in different ways.

If one disambiguates "naturalism" as physicalism (reductive or not), one gets an argument against physicalism (reductive or not). If one disambiguates "naturalism" in the Plantinga way as the claim that there is no God or anybody like God, one gets an argument for theism or something like it. Below I will assume the first disambiguation, though I think some versions of the schema will have significant plausibility on the Plantingan disambiguation.

One can replace "morally required" by such terms as "normal", "non-abnormal" or "required for moral perfection".

One can replace "to be morally perfect" by "for a perfect friendship", "to be perfectly happy" or "to know with certainty the basic truths about the nature of reality" or "to know with certainty the basic truths about ethics" or "to have virtue that cannot be lost". While (1) as it stands is quite plausible, with some of these replacements the requiredness versions of (1) become less plausible, but the "non-abnormal" version is still plausible.

Probably the hardest decision is how to understand the "cannot". The weaker the sense of "cannot", the easier it is for (2) to hold but the harder it is for (3) to hold. Thus, if we take "cannot" to indicate logical impossibility, (2) becomes fairly implausible, but (3) is very plausible as above.

I would recommend two options. The first is that the "cannot" indicate causal impossibility. In this case, (3) is very plausible. And (2) has some plausibility for "moral perfection" and all its replacements. For instance, it is plausible that if naturalism is true, certain knowledge of the basic truths about the nature of reality or about ethics is just not causally available. If, further, moral perfection requires certainty about the basic truths of ethics (we might read these as at the normative level for this argument), then moral perfection is something we cannot have. And if we cannot have moral perfection, plausibly we cannot have perfect friendship either. Likewise, if naturalism is true, virtue can always be lost due to some quantum blip in the brain, and if moral perfection requires virtue that cannot be lost, then moral perfection is also unattainable. And perfect happiness requires certain knowledge of its not being such as can be lost. Maybe, though, one could try to argue that moral perfection is compatible with the possibility of losing virtue as long as the loss itself is not originated from within one's character. But in fact if naturalism is true, it is always causally possible to have the loss of virtue originate from within one's character, say because misleading evidence could come up that convinces one that torture is beneficial to people, which then leads to one conscientiously striving to become cruel.

The second option is that the "cannot" is a loosey-goosey "not really possible", weaker than causal impossibility by not counting as possible things that are so extraordinarily unlikely that we wouldn't expect them to happen over the history of humankind. Thus, in this sense, I "cannot" sprout wings, though it seems to be causally possible for my wavefunction to collapse into a state that contains wings. Premise (2) is now even more plausible, including for all the substituents, while premise (3) still has some plausibility, especially where we stick to the "morally required" or "required for moral perfection", and make the desire be a desire for moral perfection.

If I am counting correctly, if we keep "naturalism" of the non-Plantingan sort, but allow all the other variations in the argument, we get 48 arguments against naturalism, though not all independent. Or we can disjoin the conjunctions of the premises, and get an argument with one premise that is a disjunction of 48 conjunctions of three premises. :-)

18 comments:

Evan G. said...

Hi Dr. Pruss, I was wondering where you might get arguments for (1)-- does that derive from the pursuit of truth that all humans find themselves obligated to? Forgive my ignorance!

Ray Ingles said...

One can replace "morally required" by such terms as "normal", "non-abnormal"

Of course, if you do the argument kinda falls apart. We have plenty of examples of 'poor design' in nature, so unattainable goals wouldn't be a big stretch.

Alexander R Pruss said...

Only if by "normal" you mean something like "statistically normal". But I want a beefier sort of normalcy here.

Ray Ingles said...

But I want a beefier sort of normalcy here.

Which would just devolve back to 'morally required', though, right?

Alexander R Pruss said...

I don't think so. It would still be normal, in the beefier sense, for sheep to have four legs if a genetic disease that caused three-leggedness were to overtake the majority of the world's sheep population.

Mr. Schnapps said...

I'm wondering: How would you symbolize the argument?

Also, is it possible that a good number of traits that we see as normal now are actually defects, created by the elimination of non-mutated/non-defective entities over time?

Ray Ingles said...

It would still be normal, in the beefier sense, for sheep to have four legs

So 'normal' means 'fitting a particular ecological niche'?

Seriously, can we have a definition of 'beefy normal'?

Alexander R Pruss said...

Mr. Schnapps:

It seems to me that the best way to symbolize it is in terms of a pair of modal operators, say Rp for "It is normal / morally required / not abnormal that p" and ~Mp for "It is not possible that p", a predicate D(x,p) iff x desires that p, and N says that naturalism is true.

Then we do something like, where x is a particular human, say Socrates:
1. RD(x,<x is morally perfect&rt;)
2. (p)(~Lp → ~RD(x,p))
3. N → ~L<x is morally perfect&rt;
4. Therefore, ~N.

"is it possible that a good number of traits that we see as normal now are actually defects, created by the elimination of non-mutated/non-defective entities over time?"

It's possible that something is a defect in one species and normal in a descendant species.

Mr. Ingles:

Fundamental concepts cannot be defined, on pain of vicious circularity or regress. "Normal" or "abnormal" might be a fundamental concept.

It may, on the other hand, be that we can define the normal in terms of proper function, perhaps by saying that a system is normal provided it is properly functioning. Can proper function be defined? Maybe it can be defined in terms of teleology, and maybe not. But pretty soon we'll come to something that can't be defined.

In any case, there are very few non-stipulative terms that can be given a non-trivial definition. At present, I only know of two ("adultery" and "bachelor").

In particular, I think the normal cannot be given a reductive definition to (a) facts about natural selection, (b) facts about anybody's (including God's) intentions, (c) facts about our preferences, or (d) statistical facts about the distribution of a property in a population.

Whether one can define normalcy in terms of a niche may depend on whether one understands a niche in a sufficiently normative manner.

Absent definition what can we do? Well, we can acquire a concept not by definition, but by having a bunch of examples and logical relations pointed out. Here are some:
- It's normal for adult dog eyes to send visual information to the brain.
- It is the proper task of the physician to restore the body to a normal state.
- It is not normal to eat one's ears for fun.
- It is not normal to believe something that one takes oneself to have no reason to believe.

Ray Ingles said...

I respectfully submit that quite possibly your understanding of 'normal' may presuppose the invalidity of naturalism.

For example, I have a hard time processing this statement in any other way: "If a desire cannot be fulfilled for humans, it is not [normal] for humans."

Alexander R Pruss said...

Well, it fits with Aristotelian naturalism. :-) And a number of naturalists think they can make sense of notions of proper function in evolutionary terms. I think they are wrong about that, and maybe you agree, but this is a controversial point.

I think a naturalist needs the notion of proper function, because I think the only at all promising naturalist account of mind is given by functionalism. And functionalism needs proper function. Rob Koons and I have a paper on this, but one way to see the basic issue is that functionalism needs to take account of the possibility of computational error, and the only way to make sense of the notion of computational error is to have a notion of the normal output of a computational subsystem.

Alexander R Pruss said...

Oops, my formalization has nasty typos. It should be:

1. RD(x,<x is morally perfect>)
2. (p)(~Mp → ~RD(x,p))
3. N → ~M<x is morally perfect>
4. Therefore, ~N.

Alexander R Pruss said...

Let me also add that if the naturalist can't make sense of the notion of the normal and proper function, then the naturalist is unlikely to make sense of ethical truth. See my post for today. :-)

Ray Ingles said...

"And a number of naturalists think they can make sense of notions of proper function in evolutionary terms. I think they are wrong about that, and maybe you agree, but this is a controversial point."

Hmmm. I don't actually see a problem with that - when it comes to biological functions, evolutionary accounts seem to do well. Such accounts feed into higher-level 'functions' (understood as 'intents of an agent') but don't completely determine them.

"the only way to make sense of the notion of computational error is to have a notion of the normal output of a computational subsystem."

In that sentence, don't you mean 'normal' in the sense of 'intended'? (Note Dennett's distinction about 'as-if intentionality', too.)

Alexander R Pruss said...

No, I don't think of the normal output of a computational system in the brain in terms of intention. And the naturalist certainly had better not do so if proper function is needed for a naturalistic account of mind, since then we would have vicious circularity.

Darel Rex Finley said...

What if strict, 100% naturalism is not true, but "moral perfection" in humans is also not true (or unachievable, or meaningless)? What if exceptions to naturalism are necessary to create humanity, but no exceptions to naturalism are required in humanity's day-to-day, year-to-year, century-to-century operation?

Sometimes I think the dichotomous culture war is too influential.

Ray Ingles said...

"No, I don't think of the normal output of a computational system in the brain in terms of intention."

Well, hang on. I very specifically referred to Dennett's "as-if intentionality". Evolution, for example, doesn't intend a particular function, it just winds up preserving structures that wind up carrying out functions. (Indeed, I'm not sure there's any structure in nature that serves only one function...)

Alexander R Pruss said...

Fair enough.

man with a computer said...

Does committing to that notion of 'normal' affect the argument?