 Indeed, in the process of drawing the distinction between explanation-seeking and reason-seeking why-questions, Hempel (1965c) proposed a different kind of symmetry thesis, where adequate answers to explanation-seeking why-questions also provide adequate answers to reason-seeking why-questions, but not conversely. That was very appropriate, since the purpose of reason-seeking why-questions is to establish grounds for believing that the event described by the explanandum sentence has taken (or will take) place, while explanation-seeking why-questions typically take for granted that we know their explanandum events have already occurred. It follows that, while Hempel’s conditions are meant to specify when we know why, they also entail how we know that.