The Force of the Virtual: Deleuze, Science, and Philosophy

4. Interstitial Life: Remarks on Causality and Purpose in Biology

· 133 ·· CHAPTER 4 · Interstitial Life: Remarks on Causality and Purpose in Biology Steven Shaviro The question of purpose has long haunted biology. Darwin’s explanation of evolution by means of natural selection was intended, among other things, to get rid of teleological explanations of living things. Darwin explicitly answered the “argument from design” invoked most prominently in the nineteenth century by William Paley in his once-famous book Natural Theology (1802). Recapitulating what was already an old argument, Paley said that living organisms were so intricately structured that they could not have arisen at random; they must have been produced by the deliberate actions of some Designer. The evident purposiveness and organized complexity of living things strongly suggests that they were purposefully created. This argument is so intuitively appealing that it is still being made today by creationists, or proponents of so-called “intelligent design.”1 Darwin was the first to explain the genesis of organic complexity in naturalistic terms without appealing to supernatural forces. It is important to understand how radical a move this was. In his exposition of the logic of natural selection, Richard Dawkins insists that, prior to Darwin, there was simply no satisfactory explanation for organic complexity , aside from the theistic one.2 Even Hume, who ridiculed the argument from design in his Dialogues Concerning Natural Religion (1779), “did not offer any alternative explanation for apparent design, but left the question open” (6). For Dawkins, Darwinian natural selection is still the only theory that is able to account for the complex structures and properties exhibited by living things in cause-and-effect terms acceptable to modern science, without invoking prior intentions or purposes. In other words, Darwin provides an immanent, nonteleological mechanism for the development of life. Given the theory of natural selection, 134 STEVEN SHAVIRO it is no longer necessary to invoke such teleological agencies as the hand of God, or the Lamarckian acquisition of striven-after qualities, or the workings of some inner vitalistic force like Bergson’s élan vital. Nonetheless , even the most dedicated evolutionists are unable to avoid reverting to the language of purpose. After all, living organisms, and their parts, are evidently purposive in terms of how they grow and how they relate to the world around them. It scarcely matters that this purposiveness, or intentionality, was never itself intended by any higher agency, but arose through the workings of natural selection. It still remains the case that biologists can only explain an organism by speaking as if its features (eyes, reproductive behaviors, or whatever) were purposive. When we study living organisms, we cannot get away from what Michael Ruse, in his book Darwin and Design: Does Evolution Have a Purpose?, calls “the metaphor of design.”3 Even as Ruse defends the reductionist program of orthodox neo-Darwinism against the more holistic approaches of such biologists as Stephen Jay Gould and Stuart Kauffman, he concedes that it is impossible to eliminate metaphors (274ff), teleological arguments (282ff), and pragmatic modes of evaluation (286ff) from biological discourse. “Darwinism does not have design built in as a premise,” Ruse says, “but the design emerges as Darwinism does its work and some organisms get naturally selected over others” (269). Ruse professes to find it unproblematic, and even “comforting” (270), that Darwinism both allows us and requires us to pursue an old-fashioned “understanding in terms of final causes” (289). I would like to suggest, however, that there is a greater tension than Ruse is willing to admit between the reductionist program of mainstream physical science and the implications of an unavoidable appeal to purpose, design, and final causality whenever living organisms are in question. Edward O. Wilson’s principle of “consilience,” for instance, maintains that “all tangible phenomena, from the birth of stars to the workings of social institutions, are based on material processes that are ultimately reducible, however long and tortuous the sequences, to the laws of physics.”4 But if this is correct, then biological explanations of human culture and society of the sort that Wilson copiously proffers are just as dubious a stopgap as are the sociocultural explanations that Wilson rejects. If we are to assert reductionism, then we need to follow it all the way down. We should focus upon the quantum interactions of subatomic particles, rather than upon genes and genomes, or upon organisms and their adaptations to their environment. In that way, INTERSTITIAL LIFE 135 we can...