Teleology, Embryonic Personhood, and Stem Cell Research

Article excerpt

The Necessity and Irreducibility of Teleology

From Aristotle to Darwin, philosophers and biologists have recognized that there is a principle of teleology inherent in biological entities. Aristotle, in his Parts of Animals, claims,

The causes concerned in natural generation are, as we see, more than one. There is the cause of for the sake of which, and the cause whence the beginning of motion comes. Now we must decide which of these two causes comes first, which second. Plainly, however, that cause is the first which we call that for the sake of which. From this is the account of the thing, and the account forms the starting -point, alike in the works of art and in the works of nature (Aristotle, "On the Parts of Animals," 639M0).

Following Aristotle on this point, Darwin held that biological teleology is quite evident in the natural world, and teleology is part and parcel of Darwinian natural selection and transmutation of species. Asa Gray, a friend of Darwin's, wrote that "We recognize the great service rendered by Darwin to natural science by restoring teleology to it, so that instead of having morphology against teleology, we shall have henceforth morphology married to teleology" (Gilson, p. 89). Of this passage Darwin replied, "What you say about teleology pleases me especially, and I do not think anyone else has ever noticed the point. I have always said that you were the man to hit the nail on the head" (Gilson, p. 84).

Following Aristotle, I understand the notion of biological teleology to be a logically prior and ontologically contemporaneous principle of change which is contained within beings containing heterogeneous parts such that this principle accounts for the order and developmental plan of an organism, "with the result that species exist whose characteristics are constant, as if the future of these beings had been predetermined in the seed from which they were born" (Gilson, p. 7). I will henceforth call this view finalism, which is in part an "attempt to give a reason for the very existence of [the] organization" of living things (Gilson, p. 3).

What I am caWirtg finalism is distinct from vitalism. Vitalism is roughly the idea that there is a biological or physical "ghostly" force that literally operates on living cells, such that "the activities of living organism cannot be explained solely by the interaction of their component atoms and molecules, by known chemical and physical forces" (Barry, p. 158). In the introduction to Molecular Embryology, J. Michael Barry cites the early experimental embryologist Hans Dreisch (1867-1941) as a vitalist who maintained that living things possess a "vital force unlike any force familiar to scientists - a purposeful directive force like that suggested by Aristotle" (Barry, p. 2).

The way to distinguish between finalism and vitalism is to consider this last quotation from Barry together with a comment from Gilson, who recognizes that although Aristotle talks about 'life' (zoe or vita), "he never intends by this word a principle, a force, an energy to which science or philosophy ought to have recourse, as to a cause, in order to make reasonable what we call the facts of biology" (Gilson, p. 108). If finalism and vitalism can thus be distinguished, is it possible then that finalism can be understood not as a physical vital force that works mechanically alongside the interaction of bio-molecules, but rather as a philosophical/ontological explanatory principle that helps to explain the philosophical questions about biological subject matter that have to do with what "Aristotle calls simply 'the end' (telos), the 'in view of which' (to ou eneka), the 'why' (dia ti) (Gilson, p. 2).

Teleology as an ontological reality is not reducible to physicalistic or mechanistic processes. Any mechanistic reduction simply pushes teleology to a lower level (molecular, atomic, subatomic, sub-subatomic, etc.). Pushing teleology down is not elimination. …