Friday, March 13, 2009

The argument from reason, and the explicability of the mind

It seems to me that a version of the argument from reason confirms Bayesian-confirms theism even if a naturalistic explanation of the mind is perfectly possible.

If atheism is true, how likely is it that there are creaturely minds?


P(FE)
=
P(EF)P(F) over

P(EF)P(F) + P(EF')P(F')

E= Creaturely minds exist.
F= The fundamental causes of the universe are mental in nature.
F'= The fundamental causes of the universe are not mental in nature.

Since we are trying to determine whether the argument confirms theism, we have to assume a subject that is on the fence between F and F'. In other words we have to assume that that F = .5.
Now, how likely is it that minds should exist on the assumption that the basic causes are mental. Pretty likely, it seems to me. If theism is true, then from what we know of ourselves as rational creatures, we should expect that a rational being in charge of everything would create rational beings with whom He or She could communicate. But what if God does not exist, and the basic causes were non-mental. How there can be minds is at best difficult and at most impossible to explain. A lot of things had to happen just right in the development of the human brain in order for reason to be possible, if it is even possible at all. It looks, therefore, like the existence of creaturely minds confirms theism even if we cannot show that, for example, dualism is true. The existence of creaturely reason, therefore, confirms the mental character of the universe.


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13 comments:

Hiero5ant said...

But you've smuggled in additional specification about proximate causes in your theistic scenario.

You force the naturalist to reason a priori from "fundamental causes of the universe alone" to a highly specific, local outcome of those forces. But the theist is allowed to reason from "fundamental causes of the universe" PLUS "these causes are capable of producing other minds" PLUS "these causes would want other rational beings with which to communicate". (And this is setting aside some extreme difficulties, e.g. we are never ever told how minds are created on F', so we can't be in a position to evaluate whether any given set of fundamental mental causes can create creaturely minds; and every time someone raises the AE or the ANB we are told in no uncertain terms that it is absolute hubris to assume that just because we know the gods want something, that means we can expect them to do it.)

For logical parity, you should either a) drop the ancillary assumptions about Yahweh's desires and abilities, or b) allow the naturalist to smuggle in a few billion years of cognitive evolution as an assumption.

Perezoso said...

"Creaturely minds exist".

Where's proof of this claim?

Victor Reppert said...

If there is no proof that creaturely minds exist, then there is no proof that your mind exists. Hmmm.

Victor Reppert said...

I'd love to answer you, but I just banned you from this forum.

Mark Frank said...

This is very suspect argument.

I don't think you can take seriously premises of the form: "We are discussing whether X is true. We have to assume a subject is on the fence between X and not X. Therefore we have to assume P(F) is 0.5."

For example, suppose I believe that there is an omnipotent but evil deity that created creatures with minds on earth in order that they should suffer. Call the proposition that this bizarre religion is true: H.

Now you can argue just as well that we must assume P(H) = 0.5. And we know that P(E|H) is 1 because the existence of minds on earth is part of the definition of the religion. Therefore, P(H|E) > P(not H|E). And as all other religions are subsets of the proposition that not H - then this religion is more probable than all other religions put together plus atheism.

analuon said...

Mark, the argument for the mental nature of the universe is not an argument for a specific religion. Either the universe is fundamentally teleological or it isn't. If you are unsure, a Bayesian rendering of that would be .5, not whatever atheism over all the other world religions would be.

Ilíon said...

VR: "But what if God does not exist, and the basic causes were non-mental. How there can be minds is at best difficult and at most impossible to explain."

It's actually worse than that (from the point of view of the God-deniers). It's not merely "at best difficult and at most impossible to explain," it is, in fact, utterly impossible to explain how it is that minds should come to exist in a purely cause-and-effect reality.

And it gets worse (from the point of view of the God-deniers) than just the utter impossibility of explaining how it is that minds should come to exist in a purely cause-and-effect reality.

What we mean when we speak of "explanation" typically involves looking at some problem or question from one (or a limited) point of view, specifically that which focuses upon the aspects of it which do not contradict what we already believe or want to believe and therefore tends to yield an "explanation" congenial with what we already believe or want to believe.

When we look at this issue from a different direction -- specifically, one of positing that atheism is in fact the truth about the nature of reality and then examining what logically follows from that supposition -- we will learn not only that is it impossible to explain how it is that rational minds should come to exist in a purely cause-and-effect reality, but that it is logically impossible for rational minds to exist, much less come to exist, in such a reality.


ps for the "science" worshippers: "randomness" cannot pull atheism's bacon out of the fire.

Victor Reppert said...

Mark: We put the prior for the mental nature of the universe at .5simply because we can then see what effect the evidence has on the argument more clearly. If someone were completely undecided betweeen A and B, had no idea what to decide, and this piece of evidence were presented, would it move the scale up or down? That is the question I am posing. Of course your probability for the mental nature of the basic causes of the universe may be lower. One can resist the conclusion of a good argument without irrationality, for various reasons.

Mark Frank said...

Victor

So all you are doing is comparing likelihoods. Bayes does not add anything. If P(X|H) is higher than P(X|~H) then that is some support for X. It works just as well when H is my bizarre religion. Although it is some support it is fairly meaningless without a genuine assessment of prior probabilities. Anyone can make up a hypothesis which makes an observed outcome certain.

Victor Reppert said...

But antecedent probabilities are subjective. Objective prior probabilities do not exist.

Mark Frank said...

"But antecedent probabilities are subjective. Objective prior probabilities do not exist."

This is not necessarily true. Antecedent probablities can take all sorts of forms. However, even if they are subjective

1) they still need to reflect a genuine strength of belief based on reasons - not just an arbitrary assumption

2) the resulting probability after you have applied Bayes theorem will still be subjective

You might as well stick with comparing likelihoods.

Alejandro said...

Compare:

"If the fundamental nature of the universe is rock-like, we would expect rocks to be likely to exist. If the fundamental causes are non rock-like, then how there can be rocks is at best difficult and at most impossible to explain. A lot of things had to happen just right in the development of the universe for rocks as we know them to exist. The existence of rocks, therefore, confirms the ultimately mineral character of the universe."

The problem with your argument is that it assumes from the start a fundamental difference between "mental" and "non-mental" creatures and causes, which the naturalist denies. Minds, like rocks, are just one more way matter can be arranged.

Ilíon said...

Alejandro: "The problem with your argument is that it assumes from the start a fundamental difference between "mental" and "non-mental" creatures and causes, which the naturalist denies. Minds, like rocks, are just one more way matter can be arranged.

What an interesting and insightful criticism. Let's see:

1) To assume that the concepts denoted by the terms "mental" and "non-mental" refer to two quite different things is "wrong"

2) To assume that "Minds, like rocks, are just one more way matter can be arranged" -- that is, that there is no difference between the "mental" and the "non-mental" -- is "right"


Goodness! Why didn't we see this sooner?! We must have been blinded by our religious superstit ... oops! It must be that the "non-mental" matter which is equivalent to our "mental" minds had not yet moved from Point A to Point B.


Who knows? Perhaps when the "non-mental" matter which is equivalent to our "mental" minds has moved from Point B to Point C it will be "right" to assume both 1) and 2).