This Element offers the first detailed study of Catharine Trotter Cockburn's philosophy and covers her contributions to philosophical debates in epistemology, metaphysics, moral philosophy, and philosophy of religion. It not only examines Cockburn's view that sensation and reflection are the sources of knowledge, but also how she draws attention to the limitations of human understanding and how she approaches metaphysical debates through this lens. In the area of moral philosophy, this Element argues that it is helpful to take seriously Cockburn's distinction between questions concerning the metaphysical foundation of morality and questions concerning the practice of morality. Moreover, this Element examines Cockburn's religious views and considers her understanding of the relation between morality and religion and her religious views concerning the resurrection and the afterlife.