Philosophy of Mind Seminar (Friday - Week 3, TT23)

Anankastic conditionals—like the Harlem Sentence, ‘If you want to go to Harlem, you must take the A train’—suggest two natural, often-made hypotheses. First, that an anankastic is true just in case the action prescribed in the consequent is necessary for realizing the desire reported by antecedent; for example, the Harlem Sentence just in case taking the A train is necessary for going to Harlem. Second, that every anankastic—including the Harlem Sentence—obeys modus ponens. Both hypotheses, we argue, are false. Imagine that if you go to Harlem, an assassin will kill you. In this scenario, ‘You must not take the A train, even if you want to go to Harlem’ is true, but the Harlem Sentence is false, even supposing that taking the A train is necessary for going to Harlem. Further suppose that you are unaware of the assassin; you want to go to Harlem because you believe it would be fun (but you want to avoid death more). If the Harlem Sentence obeyed modus ponens, we could conclude that you must take the A train. This conclusion is clearly false; you must avoid taking the A train. We provide a theory of anankastics—and an accompanying compositional semantics—that captures why the two natural hypotheses are false, explains the role of anankastics in practical reasoning, and identifies a restricted version of modus ponens that anankastics do obey.

This week’s seminar will be read-ahead. Please contact Will Davies (will.davies@philosophy.ox.ac.uk) if you wish to receive the paper