A viable legal system and a free society can endure and progress only by continuing to debate fundamental principles. Thus, often it is useful to return to underlying precepts in order to refine and comprehend more fully the contemporary state of knowledge. This article posits the case of the solipsist-one who denies the existence of all physical reality and maintains that his own ego alone exists-as a criminal defendant. Others, most notably Professor Lon L. Fuller, have expounded upon the manifold ways in which certain harsh necessities, externally impose upon common people, can test the rules of the criminal law. The postulate of the solipsist-as-defendant presents the inverse theme: the singular de- fendant is a psychologically extraordinary individual existing in a relatively mundane environment. It thus provides the opportunity for consideration of the ways in which internal forces of great in- tensity can shape the manners in which people behave and the way the legal enterprise functions.