Abstract
According to Jamie Whyte, the proper assignment of fulfilment conditions to an agent’s set of desires proceeds in three steps. First, one identifies various desire extinction and behavioural reinforcement conditions to obtain the fulfilment conditions of a certain subset of the agent’s desires. With these fulfilment conditions in hand, one then appeals to a principle connecting desire fulfilment conditions with belief truth conditions to obtain the truth conditions of a number of the agent’s beliefs. Finally, one uses these belief truth conditions to generate, via a third principle, the fulfilment conditions for the remaining desires. There is, however, a very straightforward reason why this strategy cannot yield the required results.