 Clarke adopted some form of rationalism in metaphysics, ethics, and theology, as exhibited in his methodology, his account of ethical truths, and in his acceptance of a fundamental rationalist principle, the principle of sufficient reason. The principle of sufficient reason was used both in Clarke’s positive metaphysical arguments and was assumed in his arguments against other philosophers, especially Spinoza, whom he chastises for failing to explain the diversity of things that exist (Yenter 2014).