On Purpose

Philosopher and perennial defender of evolution Ruse (Florida State Univ.; Philosophy of Biology; Can a Darwinian Be a Christian??) takes readers on a historical and constructive tour through one of the most importunate issues in basic metaphysics: is there any purpose behind the things—the universe, humans, nature, et al.—that are, and, if so, what is its nature and where does it come from? Ruse traces the history of three basic approaches to "purpose" in Western thought, from the Greek atomists to Charles Darwin: Platonic notions of purpose from without (common to Christian conceptions of God); Aristotelian in-built purpose (as in entelechy, vitalism, and Process philosophy); and Kantian conceptions of purpose as a heuristic device for making sense of experience. The final chapters shift to Ruse's defense of his own judgments and the relative merit of others' views, such as Thomas Nagel and Alvin Plantinga. Ruse comes down close to Jean-Paul Sartre's "existence precedes essence," arguing that humans find purpose of their own making in their lives, which he illustrates in a slightly indulgent recounting of his own family narrative. As always, Ruse defends evolutionary science while valuing the beauty and expressiveness of human culture.