Last week I was doing some research for a presentation on accessibility relations for modal logic when I ran across a curious article by Vann McGee entitled A Counterexample to Modus Ponens (JoP 82). I discussed this article a bit over dinner last night, so imagine my surprise when I see that Brit Brogaard is blogging on the topic the next morning. Of course given how busy I've been I've really no business spending time on the article. Well, except for this, some people think that modus ponens is our most basic and common form of inference. So, if our most common form of inference is not truth preserving, then that is something to be concerned about. I ran one of McGee's counterexamples by a couple of colleagues and got mystified looks in return. Here is an example from McGee of a modus ponens that appears to be valid, and yet we shouldn't believe the conclusion.

Opinion polls taken just before the 1980 election showed the Republican Ronald Reagan decisively ahead of the Democrat Jimmy Carter, with the other Republican in the race, John Anderson, a distant third. Those apprised of the poll results believed, with good reason:

1. If a Republican wins the election, then if it's not Reagan who wins it will be Anderson.
2. A Republican will win the election.
3. If it's not Reagan who wins, it will be Anderson.

I'll confess that I'm not to sure how to give an analysis of what's going on in the above passage. I initially thought we might be able to understand the conditionals as conditional assertions, but reading Lycan on the subject disabused me of that idea. Brogaard in her post favors a possible worlds analysis of McGee's proposed counterexample, but I suspect she doesn't feel a lot better about her answer than I do. I don't feel too terrible not having a response to the problem at this juncture, especially since the literature on the subject is still fresh 20 years on. Given that my philosophical superiors such as Lycan, Lowe, and Sinnott-Armstrong, have responded to the problem without quashing it makes me feel a little better in regards to my own mental abilities, though no better with regard to the problem. Fortunately I'll be doing an independent study on conditionals in the fall. I'll be reading at least Bennett's Guide to Conditionals, Lycan's Real Conditionals, and Gauker's Conditionals in Context. As always I welcome suggested readings. In the mean time, my biggest concern is that in another week or two I'm going to be standing in front of a room full of undergrads telling them that modus ponens is truth preserving, but now I'll have to extend my general caveat about some funny business with the truth-table.

Alvin Goldman (Rutgers) came and gave a talk tonight on the simulation theory of mindreading. This is the second time I've seen Goldman give a talk and as last time he seemed to have twice as much material as he had time. The talk was in connection with his recently published book, Simulating Minds. Other than providing a sketch of simulation theory and the competing theory theory, Goldman spent the bulk of his talk on the supporting evidence for the theory. This then was certainly not the typical type of talk one sees from a top philosopher. No arguments from the armchair, instead there was lots of data and citations of studies.