Date of Award
Master of Arts (MA)
N. L. Wilson
In this essay I consider various alleged exceptions to the principle of the indiscernibility of identicals -- Leibniz's Law. There are two major difficulties. First, the apparent antinomy that arises when Leibniz's rule combines with the modalities. I argue that there are a number of ways of dealing with this problem and we are not therefore obliged-to abandon or modify Leibniz's rule. Second, the unacceptable inference which results when Leibniz's rule is applied in contexts expressing mental attitudes. Here, I show how Leibniz's rule and intentional attitudes combine in a perfectly acceptable way.
I also deal with a number of other minor objections to this rule, from the current literature on the topic, all of which I hope to show present no difficulties. In fine, despite the many apparent counter-examples considered, I hope to show Leibniz' s Law, which permits the unrestricted interchange of the terms of an identity sentence, has not been falsified.
Dowling, Keith William, "Leibniz's Law and Identity" (1970). Open Access Dissertations and Theses. Paper 5785.
McMaster University Library