How should we reason about what to do? The answer offered by most recent philosophy, as well as such disciplines as decision theory, welfare economics, and political science, is that we should select efficient means to our ends. However, if we ask how we should decide which ends or goals to aim at, these standard theoretical approaches are silent. Henry Richardson argues that we can determine our ends rationally. He constructs a rich and original theory of how we can reason about what to seek for its own sake as a final end. Richardson defuses the counter-arguments for the limits of rational deliberation and develops interesting ideas about how his model might be extended to interpersonal deliberation of ends, taking him to the borders of political theory. Along the way Richardson offers illuminating discussions of, inter alia, Aristotle, Aquinas, Sidgwick, and Dewey, as well as the work of several contemporary philosophers. This is a book of major importance to a broad swath of philosophers as well as social and political scientists.