The Nature of Rationality (Princeton Paperbacks) [Paperback]

Nozick, a consummate philosopher in the analytical tradition, addresses the central issue of philosophy itself. What is the nature of rationality? If Man is the rational animal that philosophers claim, what are the principles, features, properties, methods, functions, and purposes of reason itself? Nozick concedes any attempt to ground "reasoning" fails, and all reasons for reason are circular, but not viciously circular.

For the brevity of the book, Nozick covers considerable territory. He discusses how reason itself functions and the functions themselves (interpersonal, intellectual, overcoming temptation, investment, symbolic utility, and teleological devices), using decision-value (the most technical topic), Newcomb's Problem, Prisoners' Dilemma, and other distinctions, to explicate how one arrives at rational belief, the reasons we want rational beliefs, and some rules to obtain it.

The most interesting (and disappointing) chapter is on evolutionary considerations. Few philosophers to date raise the specter of evolution at all (unless it is the topic), when, as Nozick rightly suggests, it may have its own overriding features and its own reasons and justifications. He's clearly on to an important facet and introduces issues that "limit" the need for rationality as well as require it.

My principal cavil is that he treats natural selection as a purposive agent without any disclaimers or caveats. Worse, his natural selection's purposive agency is, of course, teleological. First, that's bad form, and second, it's bad (actually wrong) evolutionary science. A subsidiary cavil is that evolution becomes a "rug" under which a-rational, even irrational, decisions may be swept (which may be true, if he is not persuasive).

Ultimately, "a rational decision will maximise an action's decision-value, which is a weighted sum of its causal, evidential, and symbolic utility" (137, passim). And, while rationality is predominately instrumental, it is not exclusively instrumental, giving excellent exemptions and reasons for them.

He considers the effect of biases, preferences ("it is a function of the preferences and believes to be rationally coherent and approximately true [and minimally consistent], and it also is a function of the mechanisms that produce such believes and preferences to produce things like that, with those functions" [149]), reflexivity, interpretation, conditionalization, probability, philosophical heuristics, and imagination on the outcomes, regardless of the cause.

Overall the book succeeds admirably in capturing the nature of rationality, those features and functions which we expect it to have, why they are important, why rationality remains important for everyone (not just philosophers), some basic rules to achieve it, principles to guide us, and its purposes in human life. He does so with economy, clarity, coherence, consistency, always reflexively to determine necessity and sufficiency. His presentation is paragon for doing and writing philosophy well.

Nozick is famous, always clear-thinking, always expressing himself briefly but to the point. His style makes the book a wonderful philosophical enterprise. But in fact, Nozick is still where social science was 10 years ago. He makes an impressive effort of combining different paradigms, evidentialism, causal theory, cognitive psychology, in one overall approach; he then applies this monstruous creature to old problems and paradoxes. The true reasons of these paradoxes, as was shown, for instance, by Bach (1984), are violations of applicability of classical rationality and decision-making theory. Not surprisingly, Nozick arrives to the same result with quite a different methodology. So, in brief, the book remains a brilliant study of ideas brought into social science years before; Nozick succeeds in beautifully arranging various paradigms. He still fails to be innovative in what concerns foundations.

Robert Nozick (1938-2002) was an American political philosopher and professor at Harvard University; he also wrote Anarchy, State, and Utopia, Philosophical Explanations, and The Examined Life.

He admits early in this 1993 book, "The political philosophy presented in Anarchy, State, and Utopia ignored the importance to us of joint and official serious symbolic statement and expression of our social ties and concern and hence (I have written) is inadequate." (Pg. 32)

He suggests, "In the study of reliable processes for arriving at belief, philosophers will become technologically obsolescent. They will be replaced by cognitive and computer scientists, workers in artificial intelligence, and others." (Pg. 76)

He asserts, "My argument that instrumental rationality is not the whole of our rationality has not been disinterested. If human beings are simply Humean beings, that seems to diminish our stature. Man is the only animal not content to be simply an animal." (Pg. 138) He later adds, "But rationality's power does not reside only in its striking individual triumphs. Rationality has a cumulative force." (Pg. 175)

This is not my "favorite" among Nozick's books, but it is still of interest to students of contemporary philosophy.