The True Intellectual System of the Universe. Wherein All the Reason and Philosophy of Atheism Is Confuted, and Its Impossibility Demonstrated. Volume 4

As a Cambridge Platonist, Ralph Cudworth advocated a rationalist ethics, opposed to Calvinism and Hobbesian materialism. Because each thing's state represents its nature, Cudworth argued, realization of the good comes through rational knowledge of it. In addition to this argument, presented in his Treatise on Eternal and Immutable Morality, Cudworth developed his earlier philosophy in The True Intellectual System of the Universe.