  A second problem arises about how to understand the relevant sense of ‘possibility of motivation’, which links the two premises. To say that motivation is possible is equivalent to saying that under certain conditions it would be actual. To understand the relevant sense of possibility, we therefore need to identify the relevant conditions under which, according to the argument, there would be motivation. The problem is that the two premises seem to require for their plausibility different conditions, and therefore different senses of ‘possibility’. In the case of the first premise, connecting the existence of reasons with the possibility of motivation, the existence of reasons plausibly entails the ‘possibility’ of motivation in only a very weak sense: perhaps nothing stronger than that the agent would be motivated if he were rational, or perhaps virtuous. In the case of the second premise, linking the possibility of motivation with the existence of desire, a much stronger sense of ‘possibility’ is arguably needed: something like there being some conditions under which the agent with his actual psychological state would be motivated.