Purpose in Living Systems

Levi Bryant and I have been going back and forth over at Larval Subjects about the role of formal and final causation in the explanation of living systems. He argues that Darwin forever banished teleology from nature, or at least showed how the apparent purposiveness of organisms is a result of an entirely non-teleological process. I’ll paste my latest response to him below:

You are still construing the argument I referenced at #6 [it is not so much “my” argument as it is Varela and Thompson’s (see “Life After Kant,” 2002, and Mind in Life, 2008)] as though it refers to the purpose or function of distinct traits or variations. That was never my claim. I fully accept that the function of an organ or a trait usually comes after its formation, and that in the course of evolutionary history, the same organ can come to have entirely unforeseen functions. The argument has to do with the immanent teleology of biological individuals, not with the contingent function of their parts. Darwin’s genius was to discover a non-teleological mechanism to account for speciation at the phylogenetic level due to chance variation and inheritance at the ontogenetic level. There is nothing in his theory, or in any additions to his theory in the last 150 years, that explains the existence of biological individuals with immanent purposes. Systems theory has offered descriptions of biological individuals in terms of attractors, but these are descriptions of behavior and not causal explanations. Efficient causality cannot offer a complete explanation for the sentient behavior of living beings. It is of course part of any explanation, but cannot be the whole explanation unless we are willing to ignore the distinct phenomenology of living systems by reducing them to the neutral language of physics (neutral in regard to the taking into account of the perspective of the system one is studying). As Etienne Gilson brilliantly argued (see From Aristotle to Darwin and Back Again: A Journey in Final Causality, 1984), no defender of teleology in nature has ever done so in order to deny the role of mechanism (efficient causation); it is only the mechanists who deny teleology. From Gilson’s perspective, while mechanistic biology can perhaps explain the specifics of the functioning of individual organisms (which is what you have been arguing), they cannot explain the existence of such individuals as such. To account for the existence of biological individuals requires a principle of immanent teleology. You’ve made reference to the reductionistic promissory notes that eventually an explanation in purely efficient terms will be provided for how DNA and RNA replication got started, thereby bypassing Varela/Thompson’s argument about the explanatory priority of autopoiesis; but as I understand the arguments of systems biologists like Stuart Kauffman (see Reinventing the Sacred, 2008), any account of nucleic acid autocatalysis, due the inherently recursive nature of such reactions, will already be in terms of formal and final causes.

A Random Fragment on the Philosophy of Biology

Randomness is a concept that Dawkins usually attempts to qualify and differentiate. The process of adaptation within his neo-Darwinian paradigm of selfish genes and natural selection is not random at all–it is driven by the brute physical agency of the Natural Selector. What is random are the mutations, which he apparently conceives of as happening one nucleic acid at a time in a fragmentary and fundamentally non-directed, non-vitalistic, non-holistic way. His approach is a consequence of Crick’s central dogma of a one-way flow of information from DNA to mRNA to protein, a paradigm blind to the work of the whole living cell to maintain, repair, and (re)generate the order of the crystalline molecules in the nucleus of each of our cells. I do agree with Stephen J. Gould‘s sense of the contingency of biological history; there are many other adjacently possible worlds. I don’t think contingency is the same as randomness, though. The history and development of life on earth, or of protons and electrons in space-time, can be full of adjacent possibilities and still display a clear directional tendency in its large scale dynamics. An Omega Point is not necessarily the imposition of an artificial design that determines the free play of nature, but can be an erotic lure embedded in the dynamics of nature itself (as in Teilhard de Chardin and Whitehead).

Stuart Kauffman talks about “exaptations,” when an organ used by one generation for one task begins to be used by another generation for entirely new, perhaps adaptive, behaviors (as with the first fish to use air bladders as lungs). This sort of mutation is not random, but the result of a sort of Baldwinian evolution through learned behavior.

I think Whitehead’s conception of Creativity is actually very close to the concepts of randomness and chaos. Chaos just needs a dancing partner, rather than conveniently and irrationally being imagined as the sole source of reality.  It’s not “God v. not God,” “theistic creationism” v. “atheistic chaosism.” It’s the presence of God and Purpose and Order mutually conditioned by the abyss of creativity and the pure, relentless renewal of nature. Randomness is always on the verge of spilling over into order, which is to say that pure novelty–absolute randomness–cannot manifest or enter into actuality but as the head of a ouroburos eating its own tales and memories, driven by the desire for the immortality of its own experiences.

In other words, randomness is the womb and the tomb of order, its creator and its destroyer. Randomness is a compost heap made of dead ideas and decaying bodies that nourishes and provokes the ongoing adventure of life and rationality.