The recent emergence, among philosophers, of the view that the activity of human reason in all its possible modes must also be historicized, including the activity of philosophizing itself, may be found in writers as diverse as Hans-Georg Gadamer, Richard Rorty, Michel Foucault, and Alasdair MacIntyre. This contemporary view of human reason contrasts with the traditional commitments of “First Philosophy,” Aristotle’s name for the knowledge of things through their ultimate causes and principles. This book challenges the prevailing historicist orthodoxies about the nature of reason and philosophy and offers the first comprehensive analysis and critique of historicism in its current philosophical form.