Abstract
Derek Parfit argues in Reasons and Persons that acting according to your present desires is more rational, or at least as rational, as acting in your long-term self-interest. To do this, he puts forward a case supporting a 'critical present-aim theory' of rationality opposed to the self-interest theory, and then argues against a number of possible replies. This article is a response to these arguments, concluding that Parfit's favouring of the present-aim theory is unfounded, and that self-interest is the better theory of rationality.