Dena Goodman here offers a fresh explanation of how critical theory broke out of the mold of an earlier tradition of discourse—the mirror for princes genre—and shaped its own course in the eighteenth century. Criticism in Action provides a historical analysis of French Enlightenment texts as actions and as the focus of critical activity in which writers and their potential readers participate. Goodman approaches texts as forces that shape the thinking and acting of the individuals engaged in the act of reading and presents new interpretations of major Enlightenment texts by Montesquieu, Rousseau, and Diderot.