, Summer 2007

Leon Kass is a physician, a professor and a superb bioethicist. He served as the chairman of the President’s Council on Bioethics. In his book Towards a More Natural Science, he has an essay entitled “Teleology, Darwinism, and the Place of Man.”

Teleology is the word that describes the theory that things naturally have goals or ends or purposes and that those ends or goals are good. The philosophical version of this theory speaks of things having “final causes or ends.” For example, the final cause of a wing is to help a bird fly, the final cause of a turkey is to provide food for human beings, the final cause of a human being is to behave in an intelligent fashion. When things perform the function that they naturally have, things go well.

Modern science doesn’t like to speak of final causes; it ostensibly limits itself to speaking of what are known as material and efficient causes. It explains that things do what they do because of the kind of matter they are and because of the source of a thing. For instance, modern science would rather say wings help birds fly because they are shaped in a certain way, rather than say wings are shaped in a certain way to help birds fly. Turkeys aren’t here to be our food but we use them “efficiently” for our food.

Kass speaks of both “external teleology” and “internal teleology.” External teleology means each part of the universe has been designed by an intelligent agent directing everything to one final purpose.

Much of the modern debate about intelligent design is about external teleology.

Kass does not wish to address external teleology but believes the evidence for internal teleology is manifest. He argues that scientists constantly utilize teleological explanations and, in fact, such explanations are indispensable to good science, especially good medicine. He notes that each thing, each seed, each embryo, has an internal directedness to becoming a certain kind of thing.

As a physician, he asks, “Should not the remarkable powers of self-healing, present in all living things, make us suspect that dumb nature in fact inclines purposively towards wholeness and is not simply neutral between health and disease?” Because we know the purpose of an eye and we know that that purpose is good, therefore we know we should heal ailing eyes and to which function we should restore them. Let me note that the modern ecological movement is spectacularly teleological; it believes it is essential to protect all species because each one makes some contribution to the whole; each has an important and good end to achieve.

Kass maintains that although Charles Darwin sought to refute the claim that nature was designed by an intelligent agent, Darwin was a firm believer that things do have an internal purposiveness. Kass describes Darwin’s purpose as this: “He wanted to account for why everything was so perfectly ordered, for why everything appeared to be designed.” He notes that Darwin’s work was “replete with teleological terms,” “not only about the functioning of individual animals but also about the overall course of evolution.”

Isn’t it fascinating that even the individual who was most responsible for launching the debate between design and evolution did not deny there was an order in things, an apparent design, that begged for explanation? Now the task is to determine which is the best explanation for the pervasive purposiveness in nature: chance or design?

Dr. Janet E. Smith is the Fr. Michael McGivney Chair of Life Ethics. She is an internationally recognized writer and lecturer on bioethics.