Aquinas, Aristotle, and the Promise of the Common Good. By Mary M. Keys. New York: Cambridge University Press, 2006. 270p. $70.00.

In her book, Mary M. Keys makes significant contributions to our understanding of Aquinas, Aristotle, and theories of the common good. Keys makes two fundamental, persuasive arguments: 1) Aquinas's account of the will's natural inclination to virtue (and consequent sociability) and his development of a theory of natural law are deliberate philosophical attempts to correct weaknesses in Aristotle's account of the common good; and 2) in correcting and improving upon Aristotle, Aquinas “is consciously laying new, deeper, and broader foundations for ethics and political science” (p. 111), foundations which are—or should be—of considerable value to contemporary secular (as well as Christian) political thought. Specifically, she argues that Aquinas's new foundations address a persistent difficulty with traditional common good theory: “how to elaborate a ‘unitary but complex’ account of the human good that does justice to the many worthwhile ways of life and the multiple genuine goods that people seek by nature and by choice” (p. 14).