Mary Wollstonecraft is recognized as an important early feminist. This Element argues that she is also an ingenious moral philosopher, who showed that true virtue and the liberty of women are necessarily interdependent. The Element consists of eight sections. After an introduction, Section 2 discusses Wollstonecraft’s concept of reason by examining its metaphysical foundation and its role as moral capacity. According to Wollstonecraft, reason interacts closely with the passions. Then, Sections 3 and 4 discuss the roles of the passions and the imagination. Reason, passion and imagination all come together in Wollstonecraft’s discussions of love and friendship, which are the topic of Section 5. Wollstonecraft values education and knowledge, but discussions of her epistemology have been rare. Section 6 analyses some aspects of her views on knowledge. Finally, Section 7 discusses Wollstonecraft’s notion of virtue, including its relations to liberty and duty. Section 8 makes some general conclusions.