This is the fourth in a series of posts on Thomas Nagel's Mind and Cosmos (Oxford 2012). The posts are conveniently collected under the rubric Nagel, Thomas. Before proceeding with my account of Chapter 4, I will pause in this entry to consider Elliot Sober's serious, substantial, and sober Boston Review review. Sober's sobriety lapses only in the subtitle (which may have been supplied by the editor): "Ending Science as We Know It."
According to Sober, Nagel " . . . argues that evolutionary biology is fundamentally flawed and that physics also needs to be rethought—that we need a new way to do science." This seems to me to misrepresent Nagel's project. His project is not to "end science as we know it" but to indicate the limits of scientific explanation. A legitimate philosophical task is to investigate the limits of even the most successful sciences. (4) Now, to investigate and point out the limits of evolutionary biology and physics is not to argue that they are "fundamentally flawed." They do what they are supposed to do, and the fact that they do not, or cannot, explain certain phenomena that certain scientistically inclined people would like them to explain, is no argument against them. After all, physics cannot explain the proliferation of living species, but that is no argument against physics. If evolutionary biology cannot explain how consciousness arises in certain organisms or the objectively binding character or normative judgments, that is no argument against evolutonary biology. To oppose Darwinian imperialism as Nagel does is not to oppose Darwinism. To suppose that every gap in our understanding can be filled with a Darwinian explanation is rightly ridiculed as "Darwinism of the gaps." (127)
Nagel's targets are not existing successful sciences. He tells us right at the outset what his target is (bolding added): "My target is a comprehensive, speculative world picture that is reached by extrapolation from some of the discoveries of biology, chemistry, and physics -- a particular naturalistic Weltanschauung that postulates a hierarchical relation among the subjects of those sciences, and the completeness in principle of an explanation of everything in the universe through their unification." (4) He goes on to characterize this worldview as "materialist reductionism" and "reductive materialism."
Nagel is therefore not opposing any science but rather a philosophical position, materialist reductionism, that is reached by a speculative-philosophical extrapolation from some of the results of the sciences.
Although Nagel admits that there are some brute facts, mind, the intelligibility of the world, and the fact that there are conscious organisms (45) are not among them. Mind is not an accident or fluke (16) and "The intelligibility of the world is no accident." One of the limits of current evolutionary theory is that it cannot explain why these remarkable fact are non-accidental. Sober does not understand why, if some facts are brute, the remarkable facts of mind, intelligibilty and consciousness are not among them:
My philosophical feelings diverge from Nagel’s. I think that Beethoven’s existence is remarkable, but I regard it as a fluke. He could easily have failed to exist. Indeed, my jaded complacency about Beethoven scales up. I don’t think that life, intelligence, and consciousness had to be in the cards from the universe’s beginning. I am happy to leave this question to the scientists. If they tell me that these events were improbable, I do not shake my head and insist that the scientists must be missing something. There is no such must. Something can be both remarkable and improbable.
Sober seems to be imputing to Nagel the following argument:
What is remarkable cannot be improbable.
Life, consciousness, reason, etc. are remarkable
Life, consciousness, reason, etc. cannot be improbable.
Now this is an unsound argument, of course: Beethoven's existence was remarkable but improbable. But this is not the way Nagel is arguing. He needn't be read as denying that there is an element of chance in the appearance of Beethoven, a particular instance of life, consciousness, and reason. His point is rather that consciousness and reason in general cannot be cosmic accidents. Sober ignores what is specific to reason, and views it as just another remarkable fact. Nagel's actual argument (see p. 86) is rather along these lines:
1. There are organisms capable of reason.
2. The possibility of such beings must have been there from the beginning.
3. This possibility, however, must be grounded in and explained by the nature of the cosmos.
4. What's more, the nature of the cosmos must explain not only the possibiity but also the actuality of rational animals: their occurrence cannot be a brute fact or accident.
I take Nagel to be maintaining that the eventual existence of some rational beings or other is no accident -- which is consistent with maintaining that there is an element of chance involved in the appearance of any particular instance of reason such as Beethoven.
Of course, Sober will still balk. Why can't reason be a fluke? Even if we grant Nagel that the intelligibility of nature could not have been a fluke or brute fact, how does it follow that the actual existence of some rational beings or other, beings capable of 'glomming onto' the world's intelligible structure, is not a fluke? In a later post I will try to beef up Nagel's argument so that it can meet this demand.
For now, though, we have a stand-off. Nagel has this deep sense, which I share, that "rational intelligibility is at the root of the natural order . . . ." (17) Sober in his sobriety does not share that sense.
There is more to Sober's criqiue than this, but this is enough for today.