temperance and prudence, whatever the person desires or values, still, the rationality of just and benevolent acts must, she thought, turn on contingent motivations. Although many found the thesis shocking, on her (then) account, it is meant to be, in a certain respect, inspiring: in a famous reinterpretation of a remark of Kant, she says that "we are not conscripts in the army of virtue, but volunteers"; the fact that we have nothing to say in proof of the irrationality of at least some unjust people should not alarm us in our own defence and cultivation of justice and benevolence: "it did not strike the citizens of Leningrad that their devotion to the city and its people during the terrible years of the siege was contingent". "Why be moral?" – later work Foot's book Natural Goodness attempts a different line. The question that we have most reason to do ties into the good working of practical reason. This in turn is tied to the idea of the species of an animal providing a measure of good and bad in the operations of its parts and faculties. Just as one has to know what kind of animal is meant, for instance to decide whether its eyesight is good or bad, the question of whether a subject's practical reason is well developed depends on the kind of animal it is. This idea is developed in the light of a concept of animal kinds or species as implicitly containing "evaluative" content, which may be criticized on contemporary biological grounds. However, it is arguable even on that basis that it is deeply entrenched in human cognition. In this case, what makes for a well-constituted practical reason depends on us being human beings marked by certain possibilities of emotion and desire, a certain anatomy, neurological organization, and so forth. Once this step is taken, it becomes possible to argue in a new way for the rationality of moral considerations. Humans begin with the conviction that justice is a genuine virtue. So a conviction that well-constituted human practical reason operates with considerations of justice means that taking account of other people in that sort of way is "how human beings live together." (The thought that this is how they live must be understood in a sense compatible with the fact that actual individuals often do not – just as dentists understand the thought that "human beings