 The second premise of the argument is a thesis in the philosophy of mind. Some mental states, like descriptive beliefs, represent how things are, and have a mind-to-world direction of fit. Other mental states are not descriptive, though they may have the same propositional content as beliefs. If you want your car to work and notice that it refuses to start, your desire does not tend to go out of existence, unlike your belief that your car is working (Smith 1987). Rather, it moves you to do something you believe would make the car work, such as call a mechanic. It has a world-to-mind direction of fit. Although particular ways of drawing the distinction remain controversial (see e.g. Sobel and Copp 2001; Frost 2014), the key idea that descriptive beliefs themselves are motivationally inert is widely accepted.