  Of course not all cases of abandoning or failing to act on a  previously formed intention count as weakness of will. I intend  to run five miles tomorrow evening. If I break my leg tomorrow  morning and fail to run five miles tomorrow evening, I will not have  exhibited weakness of will. How can we characterize  which failures to act on a previously formed intention count as weakness of will? Holton’s answer has two parts. First, he says,  there is an irreducible normative dimension to the question whether  someone’s abandoning of an intention constituted weakness of will  (Holton 1999,   p. 259).[16]  That is, there is no purely  descriptive criterion (such as whether her action conflicted with her better judgment) which is sufficient for weakness of will; in order  to decide whether a given case was an instance of weakness of will we must consider normative questions, such as whether it was  reasonable for the agent to have abandoned or revised that  intention, or whether she should have done so. In the case  of my broken leg, for instance, it was clearly reasonable for me to  abandon my intention; that is why I could not be charged with  weakness of will in that case.