 This appeal to the structure of action as the foundation for practical rationality has dramatic consequences for substantive moral theory, and an easy way to see how is to consider a terminological puzzle raised by Vogler’s presentation. She argues that her view is internalist; Bernard Williams introduced the contrast between internal and external reasons via the connection, on the one hand, or lack of it, on the other, between reasons and an agent’s motivational states (Williams 1981a); motivational states are part of an agent’s psychology; so how can an anti-psychologistic position like Vogler’s be avowedly internalist? The answer to the terminological question has to do with Williams’s own philosophical development. Following Korsgaard’s attack on his view (Korsgaard 1996, ch. 11), Williams began (albeit without announcing the changeover) to use ‘internalism’ for the claim that reasons for action can differ from person to person; there’s no level, however deep, at which they must be the same. (Williams 1995, which gives a still-psychologistic example: the alcoholic has a reason to lock up his liquor cabinet and throw away the key; the virtuous person does not; the explanation is that their characters rather than their desires differ.) So Vogler is claiming her view to be internalist in this newer sense: there are no reasons that have to be the same for everybody. Different people have different ends at different times; and since other sorts of reasons, she has argued, are optional, they vary from person to person as well. But if internalism is correct (and this was what had interested Williams in the thesis in the first place), then you can be, as the title of Vogler’s book has it, reasonably vicious; immorality of even the most extreme kind need not entail irrationality.