Born Anne Finch, this Cambridge Platonist philosopher became Viscountess Conway through her marriage in 1651 to Lord Edward Conway. Her father and husband were both high officials of state under Charles II. She was educated by tutors and shortly before her marriage began a correspondence with Henry More, who remained her philosophical mentor. After a serious illness at the age of 12, Conway suffered the rest of her life from chronic and severe headaches that kept her in constant pain for months at a time. Before her marriage she was treated by William Harvey (discoverer of the circulation of the blood); later her doctor was Francis Mercury van Helmont (1618--98). It was apparently through Helmont that Conway came into contact with Quakerism. She was influenced by Robert Barclay and corresponded with both George Keith and William Penn. Over More's disapproval, she joined Helmont in becoming a Quaker around 1675, and Quaker meetings were subsequently held at Ragley, the Conway estate. It was probably between 1677 and her death in 1679 that Conway composed her only extant work, The Principles of the Most Ancient and Modern Philosophy, which was finally published in 1690. Conway not only studied modern philosophers but also read extensively in Christian mystical literature. Her work also makes extensive reference to Jewish Cabalistic literature. The foundation of Conway's philosophical system is a natural theology based on an orthodox conception of God and an original interpretation of the Christian doctrines of the Trinity and the Incarnation. The second person of the Trinity, plays a significant role in her theory of cosmogony. Conway ascribes to God a liberty of indifference (ability to choose otherwise than He does) but agrees that He is nevertheless determined by His nature to create the best world. Conway's theory of created things is a metaphysics of monads. For Conway the physical monad is the least part of matter, but each body is divisible infinitely into smaller creatures, though not actually divided infinitely. Conway thought that only God is essentially incorporeal and all creatures have a common essence, in relation to which the difference between spirit and body is one of degree or mode. Thus, bodies are naturally changed into spirits, and vice versa, and most things are simultaneously spiritual and corporeal.