This essay examines Catharine Cockburn's moral philosophy as it is developed in her Defence of Mr. Locke's Essay on Human Understanding. In this work, Cockburn argues that Locke's epistemological principles provide a foundation for the knowledge of natural law. Sheridan suggests that Cockburn's objective in defending Locke's moral epistemology was conditioned by her own prior commitment to a significantly un-Lockean theory of morality. In exploring Cockbum's views on morality in terms of their divergence from Locke's, the author hopes to underscore (...) the extent of Cockburn's intellectual independence and her philosophical creativity. (shrink)