Abstract

Part One defends the thesis, first advanced by Aristotle, that the conclusion of practical reasoning is an action, and argues for its philosophical significance. Opposition to the thesis rests on a contestable way of distinguishing between acts and contents of reasoning and on a picture of normative principles as external to the actions that fall under them. The resulting view forces us to choose between the efficacious, world-changing character of practical thought and its subjection to objective rational standards. This is a false choice. Aristotle's own understanding of the thesis points the way to an alternative conception of practical reason on which it is at once a power to effect changes in the world and to get things right. Practical reasoning endows the action performed on its basis with a principle that is not imposed on it from outside: instead, it makes the action what it is. Properly understood in terms of the relevant acts of a rational subject, the thesis is defensible and philosophically attractive. Furthermore, it helps us understand the continuity and discontinuity that exists between the motions of human beings and those of other animals, as Aristotle showed