Modus Ponens DEFENDED

So much for the third and final attack. Thomason conditionals and Moore's Paradox do not undermine modus ponens either. We have not yet encountered a bona fide counterexample to this rule. There might, of course, be other lines of attack besides the three I discuss in this paper, but I do not know of them. In any case, it should be clear from the preceding discussion that I do not think any further attacks will succeed. In the course of defending modus ponens against McGee, Kolodny and MacFarlane, and Willer, I have put forward a semantics for the indicative conditional and an informational conception of validity on which modus ponens is valid. If this theory is more-or-less correct, then no counterexamples to modus ponens are forthcoming. Far from leading reasoners astray, this inference rule can help establish what is so according to information that incorporates the premises of an argument. © 2015 The Journal of Philosophy, Inc.