 The threat of solipsism is a very particular one for the idealism of George Berkeley. Without proof of other minds, idealism will amount to nothing but solipsism. Berkeley admits that I cannot have immediate evidence of the mind of another; what he holds is that there is “a certain collection of ideas, as directs us to think there is a distinct principle of thought and motion like until ourselves, accompanying and represented by it” (Berkeley 1710: Principle 148). While some find in Berkeley’s work another early formulation of the argument from analogy (Urmson 1982), others argue that his work should be read as putting forwards a causal argument: in the case of God, I reason that He is the cause or Author of everything in nature that I see around me; in the case of other finite spirits, I reason that they are the cause of the movements in the bodies I observe and the words that I hear (Bennett 1971 and Falkenstein 1990).