 Between 1704 and 1705–6, Lady Masham corresponded with Leibniz, at his instigation, perhaps because he hoped thereby, to have contact with Locke. This gave her the opportunity to discuss Leibniz’s philosophy with him, and for Leibniz to discuss the philosophy of her father, Ralph Cudworth. Lady Masham knew Leibniz’s philosophy only indirectly from the Journal des Sçavans of 1695, and Bayle’s article “Rorarius” in the first edition of his Dictionnaire. She takes issue with Leibniz on a number of points, including his theory of pre-established harmony, the nature of substance and free will.