Human nature and goodness › The place of practical rationality

Practical rationality concerns reasoning about what to do. One account might begin by treating a person's desires as given and asking which means serve them. That kind of reasoning can explain why someone takes a train rather than walks when they want to arrive sooner. It leaves a further question: are all the ends the person pursues equally defensible?

Foot challenges the assumption that reasons must ultimately derive from self-interest or an independently given desire. Her account tries to place concern for others within practical rationality itself. On that view, recognizing another person's need need not be an irrational interruption of otherwise sensible self-seeking.

The difference can be seen in the promise example. If the only relevant question were whether the meeting satisfied a present preference, losing that preference would appear to remove the reason to attend. But the friend relied on a commitment. The question is whether that fact supplies a reason the promisor should recognize even when another activity would be more enjoyable.

Foot's account answers by asking what practices such as promising do in human life and what it takes to participate in them well. That does not settle every conflict involving a promise. A serious emergency can change what someone should do. It does challenge the idea that the promisor's current appetite is the sole source of rational authority.