Michael Smith's recent defence of the theory shows promise, in that it captures the most common reasons for accepting a Humean view. But, as I will argue, it falls short of vindicating the view. Smith's argument fails, because it ignores the role of rationality conditions on the ascription of motivating reason explanations. Because of these conditions, we must have a theory of rationality before we choose a theory of motivation. Thus, we cannot use Humean restrictions on motivation to argue for (...) a particular conception of rationality. I will not directly criticize using a Humean conception of rationality to defend a Humean theory of motivation. For my argument implies that such criticism must come more directly, as argument over the substantive content of rationality. (shrink)