Abstract

The paper deals with the question of how the claim that nothing impossible follows from what is possible, which serves as the second premise of Diodorus' Master Argument, should be properly understood. In the first part I attempt to show that the interpretation of the thesis in the form of the following implication as suggested by R. Gaskin is not tenable: "If A and non-A follows from {A} plus the set Sigma, then not possible A follows from Sigma alone" In the second part I discuss a reconstruction of the Master Argument which adopts A. N. Prior's interpretation of the said thesis in form of the modal-logical theorem "If it is necessary that , then " but modifies Prior's suggested reconstruction in a way which should make it more plausible