Brad Delong has a provocative post here on Thomas Nagel’s new book, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False. Delong dismisses Nagel’s central argument, but that’s because Brad doesn’t really grasp Nagel’s point of view, or even the point of philosophy (at least in this post). Delong attributes the following line of reasoning to Nagel,
Suppose we think we are going south-southwest and see the sun rising before us. [According to Nagel] we don't think: "the heuristics of reasoning that have evolved because they tend to boost reproductive fitness make it likely that I am not in fact going south southwest". We think, instead: "I know the sun rises in the east! I must be going roughly east! I deduce this by my reason, and my reason is a mechanism that can see that the algorithm it follows is truth-preserving! My mind is in immediate contact with the rational order of the world! I don't just think I am going east! I know I am going east!
Delong evidently thinks Nagel is trying to answer the question, “why do we think we’re right when we hold a belief with great confidence?” when, in fact, Nagel is asking whether our minds are something more than mechanisms designed to “boost reproductive fitness.”
Delong proceeds to show, with understandable ease, that reasoning creatures like ourselves can be wrong even when we’re absolutely convinced we’re right. So, Brad concludes
Any theory that provided such an account of reason becoming an instrument of transcendence and offering guarantees of grasping objective reality would be hopelessly, terribly, laughably wrong.
Now, if you think Nagel is arguing against the very possibility of mistaken belief, then I suppose you might conclude, as Brad does, that Nagel is “hopelessly, terribly, laughably wrong,” (though, if you’d read a lot of Nagel’s work, you’d probably be more charitable).
But when Delong applies the coup de grace, saying
I cannot help but think that only a philosophy professor would believe that our reason gives us direct access to reality. Physicists who encounter quantum mechanics think very differently. . .
. . . Brad inadvertently illuminates the question on which Nagel should have been focused, as well as Delong’s own unarticulated and debatable understanding of the relationship between philosophy and science. The point of philosophy is, in part, to clarify what it means to have “access to reality,” a task that requires reflection on several issues central to Western philosophy from its classical beginnings in ancient Greece.
In Delong’s view, at least as it’s expressed in his post, physics is the ultimate arbiter on questions concerning the nature of reality. And this understanding has the implication, I think it’s fair to say, that it’s up to science to tell us what counts as having “access to reality.” W.V.O. Quine made a strong case for a conception that resembles my reading of Delong, but Quine was unsuccessful in trying to assimilate philosophy to science, and to destroy, along the way, the autonomy of philosophical (and ordinary) reason.
For Quine, the world stands to thought only as cause to effect, and, as Richard Rorty puts it in commending this view, “we understand all there is to know about the relation of beliefs to the world when we understand their causal relations to the world.” The trouble is that this understanding rules out the possibility that our thought stands in relation to reality in such a manner that features of the world can provide reasons for a particular judgment or belief.
Here’s Wittgenstein’s way of putting it, “When we say, and mean, that such-and-such is the case, we – and our meaning – do not stop anywhere short of the fact; but we mean: this-is-so.” Wittgenstein is not, of course, claiming that all our beliefs are true, but rather that there’s no conceptual gap between the sort of thing that can be thought (or said) and the sort of thing that can be the case in the world. That things are thus-and-so is both the content of experience and (if we’re not mistaken) an aspect of the world.
From this vantage point, the “materialist neo-Darwinian conception of nature” isn’t mistaken because it has failed to produce a theory that explains the power of mind to comprehend the world as it is. It’s mistaken because it regards the world only as the cause of beliefs and not as an object of beliefs, which can be assessed according to the standards appropriate to the particular beliefs in question.