Lady Conway (née Finch) was one of the very few women philosophers of the seventeenth century. She studied Cartesian philosophy with the Cambridge Platonist Henry More, who translated Descartes’ Principles of Philosophy especially for her. Barred from attending university because she was a woman, she studied by correspondence. She was thus exposed to both More's enthusiasm for Descartes and his critique of Cartesianism. She published nothing in her lifetime, but her posthumously published Principia philosophiae antiquissimae et recentissimae (1690) (English trans., The Principles of the Most Ancient and Modern Philosophy, 1692) rejects the Cartesianism of her philosophical education. Notably, she argues that on Descartes’ definition of mind and body it is impossible to account for interaction between them. Furthermore, it is contradictory to suppose that God as a perfect living being, would create a substance so unlike himself as body as conceived by Descartes. These objections lead her to posit a monism of substance, where all things consist of living particles, which she calls monads. She outlines a Neoplatonic hierarchy of being in which all things derive from God by a process of continuous emanation. Her critique of Cartesian dualism is tempered by her acknowledgment of Descartes’ achievement in elucidating the laws of mechanical motion (see law of nature). The work registers the influence of Francis Mercurius Van Helmont, who brought it to the attention of Leibniz.

See also Cartesianism; Dualism; Human Being; More, Henry; Principles of Philosophy