Nagel’s point of departure is a familiar one, based on the nature of human consciousness. Nagel’s position is that consciousness is too subjective to be reduced to a materialist explanation based on the physical nature of brains and neurons (and, perhaps, matter itself). With this as a premise, he then claims that the current Neo-Darwinist model of natural selection cannot explain how consciousness came to be and offers, as an alternative, an approach he called “natural teleology.” Orr tries to clarify this approach with the following sentence:
Natural teleology doesn’t depend on any agent’s intentions; it’s just the way the world is.Without going into details, I feel it necessary to recognize that, for many (Jürgen Habermas being a particularly good example), teleology is a highly objective process. From a mathematical point of view, one may think of it as the achievement of some goal, which may be represented as a point in some multidimensional landscape. The “world as it is,” so to speak, is another point in that landscape and teleology is concerned with how those two points are connected by a path and how that path may be found. This boils down to the mathematical problem of optimization, which means that Nagel seems to be advocating an objective technique to explain how we arrive at a subjective phenomenon, a materialist stance if ever there were one.
On the other hand the philosopher Isaiah Berlin has written very critically about the inadequacy of optimization (or, in his terminology, Utopian thinking). Berlin’s basic argument, nicely formulated in his essay “The Decline of Utopian Ideas in the West,” is that any Utopia, like that point of optimization on a multidimensional landscape, is static, meaning that, one a society or an individual “gets there,” so to speak, there is nowhere to go! Thus, in the subjective world, the only “static state” is death; and in the broader ecological scope of the natural world, even death is not a static point.
At least some of the materialist Neo-Darwinists are aware of this puzzle. Thus, the traditional Darwinian model of evolution through natural selection has given way to what has come to be called coevolution. The basic idea is that there is still a landscape; but the shape of that landscape changes to reflect what its “inhabitants” are doing. As the landscape changes, the “optimum point” on that landscape also changes. This means that, wherever you happen to be on the landscape, you have to keep rethinking the direction you want to go in order to get closer to your goal. This strikes me as what makes “natural” teleology natural, rather than merely mathematical. Back in October of 2011, I suggested that, because of coevolution, there may never be that “ideal” cure for the common cold. Every time new medication comes along, the landscape changes, and the cold virus follows natural selection according to a change in the criteria for fitness. (In that same post I suggest that the common cold is not that different from malware.)
Nagel never mentions coevolution in his book. However, Orr does not cite it either as a materialist school of thought. Many of its advocates came out of early research in artificial life, although Darwin himself described it in On the Origin of Species. To be fair, however, Nagel’s book is a short one, only 130 pages, which he uses simply to establish his position. Here is hoping that he develops that position in greater depth and that his digging will lead him to coevolution!