ABSTRACT
The legacy left by Rene Descartes in Meditations on First Philosophy and his other works sparked a critical dialogue that has evolved throughout modern philosophy. The continental rationalist tradition derived some of its central tenets from Descartes. Baruch Spinoza and Gottfried Wilhelm Leibniz use notions of innate ideas and the concept that true knowledge is to be rationally deduced from basic principles. But the rationalists criticized particular aspects of Cartesian metaphysics. The eighteenth-century German philosopher Immanuel Kant was scandalized that neither rationalism nor empiricism could solve the problem of the existence of the external world introduced by Descartes. Kant's critique of rationalist metaphysics in the eighteenth century halted the development of rationalism. Philosophers continue to rework Descartes's ideas. One of the most famous contemporary examples is twentieth-century American philosopher Hilary Putnam's brain-in-a-vat thought experiment. Putnam's scenario has been the subject of much debate among epistemologists, philosophers of language, and philosophers of mind working within the framework of twentieth-century analytic philosophy.
