Philosophical Letters

Thomas Hobbes and René Descartes both came to dinner in Paris in the 1640s at the house of William Cavendish, Marquess of Newcastle. His wife Margaret, by her own account, never got past small talk with either. Twenty years later Margaret Cavendish answered them in print. Her case is that matter needs no soul, no spirit and no push from another body, because it moves and knows by itself. The book of 1664 takes the form of letters to an unnamed "Madam" who has asked for her opinion of four famous authors. It was not a real correspondence. The men she wanted to answer would not dispute with her in print, so she invented a reader who would ask. She starts with Hobbes's Leviathan, setting its politics aside, and denies that we see because an object presses on the eye: the eye's own matter, she argues, makes a copy of what is in front of it. Against Descartes, whom she knew only from passages translated for her, she rejects a mind made of something other than body and denies that one body can hand its motion to another. Against Henry More, the Cambridge Platonist, she refuses an immaterial spirit set over nature to direct dead matter. Jan Baptist van Helmont, the Flemish physician and chemist, has the third of the four sections to himself. The fourth turns to other writers, William Harvey and Galileo among them, and to questions about her own earlier treatise. Throughout she keeps theology out and argues from nature alone. On her account the world holds one kind of thing, and the puzzle of how a mind could move a body, which occupied Descartes's readers, never arises. She sent More a copy, and he told his friend Anne Conway, herself a philosopher, that the author could be sure nobody would trouble her with a reply. The letters she had back from scholars made almost no attempt to argue with her. The exception was Joseph Glanvill, a clergyman who wrote in defence of the Royal Society: he took up her positions and argued back in his letters to her.