IN MARGARET CAVENDISH’S first serious philosophical work, the 1655 Philosophical and Physical Opinions, which she often acknowledged as her favourite among her many writings, she states, “I am my Lords Scholar.” This claim might seem like the loving proclamation of a grateful wife, but given the patronage dynamics of the mid-seventeenth century, it is actually much more. By citing the role her husband William Cavendish, the Marquess (later Duke) of Newcastle played in exposing her to the natural philosophy of the time, she is also indicating that he is the authority who by his support becomes the patron who validates the veracity of her ideas. In two other early works, Philosophicall Fancies and Poems, and Fancies, both published in 1653, Cavendish also recognizes the role her husband’s brother, Sir Charles Cavendish, played in supporting her forays into scientific thinking: “I do here dedicate this my Work unto you,” she writes in Poems, and Fancies, “not that I think my Book is worthy such a Patron, but that such a Patron may gaine my Book a Respect, and Esteem in the World, by the Favour of your Protection.” And, moreover, to neglect to acknowledge his patronage would be a grave error on her part, as she also emphasized in Philosophicall Fancies: