Modern Darwinian biology seems to promote nihilism, for it seems to teach that there is no rationally discoverable standard in nature for giving meaning to life. The purpose of this article is to argue for a revival of Aristotle's biological teleology as a reasonable alternative to biological nihilism. The article begins with Edward Wilson's vain struggle against nihilism. Then it is argued that a teleological understanding of nature is assumed in the practice of medicine, as illustrated by one case from Oliver Sacks' neurological practice. The article then considers the importance of biological teleology for Aristotle's moral and political philosophy, and attention is given to some points of agreement and disagreement with contemporary sociobiologists. The main part of the article is then devoted to a defense of Aristotle's biology against the five objections that might be made by a Darwinian biologist. Finally, the article illustrates the practical implications of this issue for bioethics by considering the recent work of Engelhardt.