My Call Into "Catholic Answers" with Trent Horn

 LINK (HT: Real Atheology)

The Moral Psychology Argument for Atheism

(Note: I am clearing out my backlog of draft blog posts but I am officially on a hiatus from blogging. What this means is that while you are free to comment on this post, readers should not expect engagement from me anytime soon.)

Updated 7-January-2022

John Jung Park's 2017 paper revives an old argument for atheism: errors in human moral judgment due to various psychological biases provides a reason to think God does not exist. Park's argument refers to "framing effects." Following another one of Park's papers, we may say that moral framing effects occur when 

morally irrelevant differences in the way a scenario is presented affect people’s moral judgments regarding that scenario.

Here's an example (taken from Park's 2021 paper):

Save vs. Kill: Petrinovich and O’Neill (1996, Exp. 1) reported that some participants indicated that they would do one act when the act was described in terms of how many people it would save (Save condition) but would not do that act when the act was described in terms of how many people it would kill (Kill condition), even though they had been told that the act would have both effects.

The Evidential Argument from Mind-Brain Dependence: A Reply to Bilbo

[This post was originally published on The Secular Outpost on November 26, 2006. It was republished here on November 7, 2021 with the date manually adjusted to reflect its original publication date. The link was also updated to its current location.]

In my response to Victor Reppert's anti-naturalistic argument from pain, I stated that a more specific fact (consciousness is dependent upon the physical brain) about consciousness is antecedently more likely on naturalism than on theism. Bilbo provided several feedback messages in response to this claim. As I read him, he thinks the argument is no threat to Christian theists. It is apparently his view that mind-brain dependence is at least as probable on Christian theism as on naturalism, since Christian theists believe in specific, sectarian doctrines that raise the probability of mind-brain dependence. Since I think Bilbo is wrong about this, I'll explain why.

First, here is the logical form of my evidential argument.

Let D = the mind is dependent upon the physical brain.
Let T = classical theism
Let N = metaphysical naturalism

(1) D is known to be true.
(2) T is not much more probable intrinsically than N.
(3) Pr(D/N) > Pr(D/T).
(4) Other evidence held equal, T is probably false.

Note the modest nature of this argument. It doesn't claim that theism is probably false; it merely claims that evidence (D), by itself, favors N over T. This distinction is crucial since it allows for the possibility that there could be other evidence that both favors T and outweighs the evidence for N provided by D. Thus, D should be understood as a prime facie reason for rejecting T.

Let me now turn to some of Bilbo's specific comments.

Bilbo: "My first problem is that it seems more accurate to say that minds *are* the physical brain on Naturalism (not merely dependent on them). And since this has not been demonstrated, it would beg the question to assert that the postulate that "minds are the physical brain" provides evidence for Naturalism."

That would indeed beg the question, which is why I never said that! My argument is an inductive argument. It would be illegitimate to state the evidence in such a way that entails the hypothesis to be proved. Therefore, I'll stick with my original formulation of the premise ("the mind is dependent upon the physical brain").

Bilbo: "But the Christian views I mentioned also make it antecedently probable that minds will be dependent on the brain. Let's use the structure of your argument with Christian non-reductive physicalism (hereafter NRP)..."

If theism is improbable given D, then so is Christian theism (or any other more specific belief system that entails theism). Christian theism entails theism; therefore it cannot be more probable than theism. Premise (4) entails that, other evidence held equal, Christian theism is probably false.

I don't deny the potential relevance of sectarian doctrines to the issue of whether my argument is sound. They could raise Pr(D/T) or lower Pr(D/N). In order to assess the evidential significance of such doctrines, we would need to apply a principle that Draper calls the "weighted average principle" (WAP). Let H represent some Christian doctrine. Then WAP can be represented as follows.

Pr(D/T) = Pr(H/T) x Pr(D/T&H;) + Pr(~H/T) x Pr(D/T&~H)

This formula is an average because Pr(H/T) + Pr(~H/T) = 1. It is not a simple straight average, however, since those two values may not equal 1/2.

Let us consider, then, Christian non-reductive physicalism (CNRP), which Bilbo proposes as a specific doctrine that he believes raises the probability of D given (Christian) theism. Bilbo defines CNRP as "the non-existence of all supernatural beings, except for those that are or were at some point divine (angels, demons, God, etc.)." Bilbo claims that CNRP "entails the nonexistence of disembodied human minds." Using WAP, we obtain the following.

Pr(D/T) = Pr(CNRP/T) x Pr(D/T&CNRP;) + Pr(~CNRP/T) x Pr(D/T&~CNRP)

In order to reject my evidential argument, therefore, Bilbo would need to show that CNRP raises Pr(D/T) so that it is greater than or equal to Pr(D/N) by using the above formula. Does CNRP do that? I shall leave the question as an exercise for the reader.

(Note: I have borrowed heavily from ideas in another paper by Paul Draper, "More Pain and Pleasure: A Reply to Otte." I am, of course, responsible for any errors in my post.)

Militant Agnosticism

[This post was originally published on The Secular Outpost on January 31, 2006. It was republished here on November 7, 2021 with the date manually adjusted to reflect its original publication date.]

I recently received an email from an agnostic named Dan who was, ironically enough, quite militant about his agnosticism! According to Dan, "one cannot logically be an atheist" because "a negative can never be proven." Notice, however, the statement "a negative can never be proven" is itself a negative statement. Either the statement "a negative can never be proven" can itself be proven, in which case the argument is self-refuting, or it can't be proven, in which case it doesn't provide a reason to reject atheism. I make this and other points in my essay, "Is a Sound Argument for the Non-Existence of a God Even Possible?"

When I referred Dan to the article, I explained that there are actually two ways to prove the nonexistence of something. One way is to prove that it cannot exist because its very concept is self-contradictory (e.g., square circles, married bachelors, etc.). The other way is by carefully looking and seeing. Both of these methods can and have been used to disprove various conceptions of God.

Dan took issue with the second method because it "presumes your senses and abilities are w/o bound." Not really; the fact that we are finite beings does not prevent us from legitimately concluding that, given some body of evidence, a particular hypothesis is more probable than another hypothesis. This goes for conclusions about God's existence just as it does for other areas where inductive logic is used, such as weather forecasting and criminal forensic investigations.

I suspect that Dan is holding both theism and atheism to a much higher evidential standard than we apply to other empirical questions. The fact that we might discover some new item of evidence in the future that supports a contradictory conclusion in no way undermines the fact that the evidence we have today supports an explanatory hypothesis. For example, the probability that the Declaration of Independence was signed on July 4, 1776 is extremely high, but it is not 100%. I suppose it is logically possible that in the future someone might discover historical evidence demonstrating the Declaration of Independence was signed on February 2, 1775. But the fact that such a thing is logically possible is irrelevant to the inductive (probabilistic) conclusion that the Declaration was indeed signed on July 4, 1776. In other words, a conclusion can be highly probable even if it is possible that the conclusion is false.

As a nontheist, I don't demand that someone prove to me that the existence of God is absolutely certain (i.e., has a 100% probability). I would settle for an argument showing that the total relevant evidence merely makes the existence of God highly probable. Similarly, we don't need absolutely certainty (i.e., 100% probability) in order to know that there is no God. We can use inductive arguments to show that God's nonexistence is more likely, even much more likely, than God's existence. And, indeed, I think there are inductively correct arguments that show religiously significant conceptions of God--such as the God of Judaism, Christianity, and Islam--do not exist.

After corresponding with presuppositionalists who make the ridiculous claim that there are no atheists, I thought I had heard everything. I was wrong. After reading my defense of the second method of proving the nonexistence of something, Dan then proceeded to tell me that I am "really" an agnostic but I just refuse to admit it. This remarkable conclusion is supposed to follow from the fact that I don't claim to be able to prove with absolute certainty that God doesn't exist. The fact of the matter, however, is that ordinary usage of the word "atheist" does not support that conclusion. There is no requirement that one has to be absolutely certain that there is no God in order to qualify as an atheist. I have never claimed to be absolutely certain that atheism is true, but it doesn't follow that I merely lack belief in God or that I am not an atheist. Rather, I believe God's existence is very improbable.

To make an analogy, I don't know with absolute certainty that the sun will rise tomorrow, but I am highly confident that it will (i.e., it has an epistemic probability for me of >99.999%). That hardly means I am "agnostic" about whether the sun will rise. (In other words, one can hold a belief without assigning an epistemic probability of 100%.)

I'm reminded of Taner Edis's recent discussion about individuals who claim that everyone is born 'my' way (i.e., theists who claim that everyone is born theist, atheists who claim that everyone is born atheist). Granted, Dan's claim (that I and at least some other atheists are really agnostics) is not quite in the same category as the claims that Taner was discussing. But it is interesting to me that so many people's argumentative strategy includes defining one's 'opposition' out of existence!