Rene Descartes's motto challenges his would-be historians: "He lives well who hides well." He hid even in the Discourse on Method, where he professed to recount the story of his "entire life," but said almost nothing about his childhood and youth. He mentioned neither family nor friends, and he boasted a total freedom from irrational passions. In the Discourse, which presented a new way of achieving certain truth through mathematical reason, Descartes stressed just one event, a day of thinking at the beginning of winter, 1619. Tucked away in an unpublished notebook, however, Descartes also left the Olympica, which documented the wildly irrational dreams he had the night of November 10, 1619, and gave his own enthusiastic interpretations. Embarrassed scholars have tried to reason away this record and even the dreams themselves. Adapting clinical methods to historical research, John Cole offers the first systematic interpretation of the Olympian dreams. He argues that they expressed and masked Descartes's unresolved conflicts: his guilt at having rejected the law career for which he had been trained and which his lawyer father had wanted him to pursue, and his shame over early failures to satisfy the high expectations of his friend and mentor, Isaac Beeckman. Cole shows us how a critical historian can make sense of such irrational material and lets us see the creation of an egocentric and rationalist philosophy.