Someone I don’t know phones me at my office in New York from — as it might be — Arizona. ‘Would you like to lecture here next Tuesday?’ are the words he utters. ‘Yes, thank you. I’ll be at your airport on the 3 p.m. flight’ are the words that I reply. That’s all that happens, but it’s more than enough; the rest of the burden of predicting behaviour — of bridging the gap between utterances and actions — is routinely taken up by the theory. […] the theory from which we get this extraordinary predictive power is just good old commonsense belief/desire psychology.