  As Williams observes, any view of this Davidsonian kind has to overcome an obvious problem. We can have reasons which do not motivate us to act (e.g. if we are unaware of them), and we can act in ways for which we lack any actual practical reasons (e.g. if we are mistaken about what our reasons are). Identifying an agent’s practical reasons, it seems, neither entails nor is entailed by giving an explanation of her actions. On this reading, Williams suggests that this problem arises simply due to agents’ error and ignorance, and he offers a way to fix the Davidsonian approach. To think that a fact is a reason for an agent to act is not to think it is an explanation of an action that she actually performs, but rather it is to think it an explanation of an action that she would have performed (or would have been somewhat motivated towards performing) if not for her error or ignorance. The concept of a practical reason must be the concept of an explanation of counterfactual (motivation towards) action: action under the condition of full and valid reasoning and exercise of imagination from a belief-set purged of error and ignorance (‘sound deliberation’). He claims that the idealization contained in this counterfactual condition is enough to make these reasons normative and not merely explanatory.