Book Review: Thomas Nagel, The Last Word
The shortest summary of the impression Nagel's book causes to me, is that it strikes me as "quixotic". But I am saying this not meaning that it is idealistic and brave, but in a sense that intends to reflect the original character of Don Quixote: I picture Nagel as charging against windmills. He takes ordinary things and turns them into big deals, blowing out of proportion the philosophical problems they pose. Many of the things he says in the book are true; it's the seriousness and deepness he reads into these things being true what I disagree with.
The main argument of the book can be easily summarized: Reason is universal and fundamental. All positions that describe our rational capabilities (be it in logic, in science, or in ethics) as contingent upon our culture, society, upbringing, genes or evolutionary development, are ultimately inconsistent. The rational kinds of claims they try to subvert (that such-and such method of reasoning is valid, that this-or-that is the way the world is, that a given action is right or wrong) are basic to our thinking; there is no way a psychological, sociological or biological explanation of them can trump over them.
Insofar as his target are the species of subjectivism and relativism so popular in the humanities, Nagel has an easy task, although one that is perhaps beneath a philosopher as well-known and learned as him. His basic argument is that if someone makes for example a scientific claim p, and someone else says for example "but p is just what you believe because of your culture", this is also a claim to be evaluated rationally, just as we evaluate p itself. There is no way of judging reason from the exterior; all our thought is conducted within it. This is an argument and a conclusion with which I basically agree.
The problem is with how Nagel interprets this result. He "inflates" it as establishing a Platonic-Cartesian kind of picture, in which mind has the capacity of grasping reality through reason, and this capacity cannot be accounted for in scientific/naturalistic terms (as the result of evolution for example). Nagel thinks that any naturalistic account of reason must fall guilty of "standing outside it" and calling into question its absoluteness, by transforming it into a contingent feature of an animal species evolved by chance. And he thinks his earlier argument precludes this possibility, and thus dismisses naturalism together with subjectivism. (The fact that most English-speaking philosophers are naturalists and not subjectivists should have warned him that this step is not so easy). So what positive account does he offer of reason? In the last chapter, the most interesting and less predictable, the argument takes an unexpected turn: he admits that the only major option left is a religious or quasi-religious worldview, and confesses that he does not accepts it pehaps for a possible prejudice against it -he says he does not want God to exist! Understandably, religious reviewers (see here and here and here) have shown glee at this pronouncement -they can say (or well, they are too polite to say it, but they surely think) look, a major atheist philosopher admits that reason leads him to religion, and that only his irrational prejudices prevent him from accepting the conclusion!
What leads Nagel in the wrong direction, I think, is that he thinks of our judgments as forming a hierarchy, with things like modus ponens or "2 + 2 = 4" at the top and particular claims in sciences like biology or sociology much lower in the scale. Given this picture, to give an account of "Reason" (which sits at the top) from naturalistic premises is inevitably to degrade it, and a Platonic metaphysics must follow. If one replaces this picture with the Quinean one of a web of beliefs, some of which are more central than others but none of which is ultimately immune to revision, the perplexities mostly disappear. Principles of logic and mathematics are central to our reasoning in fact; a naturalistic account of how we came to believe them (perhaps because they are ways of thought that work in practice and have survival value) can be integrated with the principles themselves in a consistent picture, strengthening them despite having been reached to partially by use of them. Nagel assumes the question is "why is reason justified?", and as neither evolution nor anything else which is contingent can justify it, the answer must be metaphysical (or if there is no answer at all, even worse: Reason with capital R is a fundamental feature of the world). But reason needs no other justification than its lying at the central and most stable position of our web of belief, which does not give it an absolutely privileged status and still permits to give a naturalistic explanation of how it came to be there.
Coherentist, holistic thought of this kind seems to be anathema to Nagel, but he never argues against it. For example, he says that proposals for replacing classical logic with other logic, quantum logic for example, can be answered simply by use of classical logic (by whose standards, obviously, the other logics lead to contradiction). This does not acknowledge the possibility that surprising empirical discoveries may force us into developing new ways of thought to cope with them, which may be absurd and inconsistent by previous standards (just think of quantum mechanics!) He just says that when we discover that something previously thought contradictory is possible and even true, we do it by using higher logical principles which remain unchallenged -again the hierachical picture. This is in my opinion not a good description of scientific revolutions, in which what happens is more like the substitution of a way of thinking about the world for a radically new one when the old one becomes pragmatically inadecuate.
In summary, I found this book a bit disappointing after reading other works of Nagel like Mortal Questions and The View from Nowhere. The essays in the first one contain many interesting discussions on a variety of subjects little discussed by other analytical philosophers, and the second one is a deep exploration of most of the central questions of philosophy; though I disagree with many of the conclusions, they are definitely worth-reading books. This one contains a valid but not very necessary refutation of some trendy postmodernist discourses (after all, they refute themselves, don't they?), plus the attempt to interpret this refutation as meaning the soundness of old-fashioned metaphysics -a misguided attempt and one that accepts the basic mistake of the postmodernists, that the only possible options are "Absolute Reason" or "All is Text", Plato or Derrida. Confronted with this option, most non-religious contemporary thinkers would go for Derrida. Fortunately it is not necessary.
PS: there is a good review by Simon Blackburn here.