 Before Caroline of Ansbach became the Princess of Wales, she was tutored by Leibniz. Leibniz did not join her in England, and they corresponded across the channel. In one of these letters he attacked prominent views in England that Leibniz considered dangerous to natural religion. After mentioning materialism and Lockean doubts about the soul, Leibniz chastises Newton twice. (Newton and Leibniz had sparred earlier over the priority of discovery of the calculus.) Clarke, who with Newton was attending Caroline’s court, came to Newton’s defense. A series of five letters passed through Caroline between Leibniz and Clarke over a wide range of issues. Caroline is significant not only for her contributions to framing the debate for each correspondent but also as an important context for understanding the letters (Meli 1999). Leibniz is trying to maintain Caroline’s commitment to his system, while Newton and especially the more sociable Clarke are working to convert her with arguments and experimental demonstrations in person. She continued to challenge Clarke and pledge loyalty to Leibniz until his death, but starting around the time of the third letter, it seems that Clarke had won her over at least to the existence of the vacuum, which would be difficult to maintain without going for the rest of the Clarkean-Newtonian picture (Brown 2004, 93–98).