A study of rationalist philosophy in the European Enlightenment period of the seventeenth and eighteenth centuries. Selected writings of Descartes, Spinoza, and Leibniz are analysed and interpreted. As we discuss each author's ideas, we will evaluate their positions on: the limits of reason, the intelligibility of revelatory truth, the existence of God, the divisibility of reality, the role of nature, and the ethics and politics of human life.