INDETERMINACY, OPACITY AND THE IDENTITY THEORY

Consider the following argument, which I will label Argu-ment A. Argument A Premise A1: If we cannot imagine any decisive evidence for or against P, then it is indeterminate whether P. Premise A2: We cannot imagine any decisive evidence for or against the claim that Jane is in mental state M. Therefore, Conclusion A: It is indeterminate whether Jane is in mental state M. Arguments of this form might raise some eyebrows. But, questionable or not, this kind of move —from lack of a conceivable test, to a lack of a fact of the matter — shows ∗ This paper owes a great debt to Tim Kenyon, whose arguments I am concerned to rebut. It is with great pleasure that I dedicate it t