Some years ago, Hilary Putnam published a paper called “Is Logic Empirical?” [7] in which he argued that quantum mechanics provides an empirical case for revising our views about logic. (The paper was republished in his collected works as “The Logic of Quantum Mechanics”. Page references will be to the reprinted version.) In 1974, Saul Kripke presented a talk at the University of Pittsburgh called “The Question of Logic,” offering a detailed rebuttal of Putnam's case. As of this writing, almost 40 years later, Kripke's paper still hasn't appeared in print and apart from my 1978 dissertation and a paper I published 28 years later [9], very little has been written on the disagreement between Putnam and Kripke. This is unfortunate; the issues are well worth investigating. In my 2006 paper [9], I adopted the device of writing about Paul Kriske and Prof. Tupman out of deference to the fact that there is no published version of Kripke's talk. Here I'll simply write directly about Putnam and Kripke. If I get Kripke wrong, I hope he'll let us know.

As for the plan of the paper, we begin by reviewing Putnam's arguments; after that we move to Kripke's rebuttal. This will lead to a larger discussion of what logic and the empirical might have to do with one another.