Akrasia and Uncertainty

According to John Broome, akrasia consists in a failure to intend to do something that one believes one ought to do, and such akrasia is necessarily irrational. In fact, however, failing to intend something that one believes one ought to do is only guaranteed to be irrational if one is certain of a maximally detailed proposition about what one ought to do; if one is uncertain about any part of the full story about what one ought to do, it could be perfectly rational not to intend to do something that one believes one ought to do. This paper seeks to remedy this problem, by proposing an anti-akrasia principle that covers cases of uncertainty (as well as cases of such complete certainty). It is argued that this principle is in effect the fundamental principle of practical rationality.