Margaret Cavendish was a natural philosopher and feminist who between 1653 and 1671 wrote some twenty-six works, including fourteen scientific books about atoms, matter and motion, butterflies, fleas, magnifying glasses, distant worlds, and infinity. Her vitalist–materialist view held that human beings are matter in motion who think. She argued that her age had produced many feminine writers, rulers, actors, and preachers and was perhaps a feminine reign. Cavendish was a pioneer, both as a feminist and a natural philosopher. While standing up for the rights and intellectual abilities of women, she attempted to address the most fundamental ontological and epistemological questions of philosophy. She also anticipated and articulated ideas associated with future philosophers, such as Spinoza’s pantheism, Leibniz’s vitalism, Hegel’s dialectics, and Marx and Engels’s dialectical materialism. In synthesizing ideas into her own system of a vitalistic dialectical form of materialism, she paved the way both for the “new science” and the “new philosophy” that emerged during the seventeenth-century Scientific Revolution.