Post Author: Bill Pratt

In part 1 of this series, we argued that physicalism and determinism are self-refuting because they undermine rationality.  At the end of part 1, we said that there are three conditions of rationality that physicalism does not allow, and Dr. Moreland explains them below:

First, humans must have genuine intentionality; they must be capable of having thoughts and sensory awareness of or about the things they claim to know. For example, one must be able to see or have rational insight into the flow of an argument if one is going to claim that a conclusion follows from a set of premises. We can simply see that if you have: 1) If P, then Q, and, 2) P, therefore, you also have, 3) Q. This requires an awareness of the logical structure of the syllogism itself.

 As we saw earlier in this chapter, intentionality is a property of mental states, not physical ones. Thus, this first feature of rationality is incompatible with physicalism . . . . Intentionality is not a physical property.

The second factor is the enduring I.  Moreland explains:

Second, in order to rationally think through a chain of reasoning such that one sees the inferential connections in the chain, one would have to be the same self present at the beginning of the thought process as the one present at the end. As Immanuel Kant argued long ago, the process of thought requires a genuine enduring I.

In the syllogism above, if there is one self who reflects on premise 1), namely, “If P, then Q,” a second self who reflects on premise 2), namely, “P,” and a third self who reflects on the concluding statement 3), namely, “Q,” then there is literally no enduring self who thinks through the argument and draws the conclusion. As H. D. Lewis noted, “One thing seems certain, namely that there must be someone of something at the centre of such experiences to hold the terms and relations together in one stream of consciousness.”  

However, we have already seen in a previous blog post that physicalism denies a literal, enduring I, and thus physicalism is at odds with this necessary condition of rationality.

The third necessary condition for rationality is libertarian freedom of the will.

Finally, rationality seems to presuppose an agent view of the self and genuine libertarian freedom of the will. There are rational “oughts.” Given certain evidence, I “ought” to believe certain things. I am intellectually responsible for drawing certain conclusions, given certain pieces of evidence. If I do not choose that conclusion, I am irrational.

But “ought” implies “can.” If I ought to believe something, then I must have the ability to choose to believe it or not believe it. If one is to be rational, one must be free to choose her beliefs in order to be reasonable. Often I deliberate about what I am going to believe, or I deliberate about the evidence for something. But such deliberations make sense only if I assume that what I am going to do or believe is “up to me”—that I am free to choose and, thus, I am responsible for irrationality if I choose inappropriately. But we have already seen that physicalism . . .  rule[s] out libertarian freedom.

Moreland, thus, concludes that physicalism rules out the possibility for rationality.  “It is self-refuting to argue that one ought to choose physicalism . . . on the basis of the fact that one should see that the evidence is good for physicalism. Thus, substance dualism is the best view of the self and is most consistent with the preconditions of rationality.”