The Genesis of Berkeley's Theory of Vision Vindicated

Berkeley's Theory of Vision, or Visual Language Showing The Immediate Presence and Providence of A Deity, Vindicated And Explained was published in 1733, occasioned by an anonymous letter of the previous year to the London Daily Post Boy. The letter criticized Berkeley's New Theory of Vision, which had been published in 1709, but which had been appended to Berekely's Alciphron, published in 1732. No one has ever identified the author whose criticisms led Berkeley to his Theory of Vision Vindicated. Circumstantial evidence presented here suggests that the author was Catherine Trotter Cockburn. Part of the evidence is the brilliance of her interpretation of Locke, whose position is defended in the letter against Berkeley.