Abstract

In this dissertation, I argue that the distinction in contemporary ethical literature between "internalism" and "externalism" as theories of moral motivation has not been adequately or uniformly drawn. Thus, William Frankena, Thomas Nagel, Ronald Milo, and Christine Korsgaard actually present four different versions of the distinction. I further argue that the only version that is philosophically interesting is the one suggested by Christine Korsgaard, which I refer to as Rational Internalism. Rational Internalism is the view that the genuine and authentic recognition of a moral obligation by reason necessarily entails the motivation to act morally. ;I also argue that Rational Internalism can be defended against the following objections which have been raised against internalism generally: Internalism must be false because it entails that reason always takes precedence as a motivator among other motivating influences ; it is possible for a person to have an obligation and not be motivated by it ; it is possible to make a moral judgment and not be motivated by it ; and, more generally, it cannot account for the phenomenon of moral indifference . I further argue that Rational Internalism can be defended against two objections raised against Rational Internalism specifically: Rational Internalism is inadequate because it does not allow compassion its proper role as a moral motivator ; and reason, by nature, lacks motivational influence . Since this last objection is the most formidable, I devote an entire chapter to an evaluation of the differences between Kant and Hume on moral motivation. Here, I argue that the differences between them are more metaphysical than ethical, and that Hume does not convincingly argue that reason lacks motivational efficacy. ;Finally, I provide an exegesis of Thomas Nagel's argument for Rational Internalism, and argue that criticisms of it raised by E. J. Bond and Stephan Darwall are unsuccessful. Since many of the objections to Rational Internalism result from the lack of a careful presentation of this theory of moral motivation, I conclude with a formal statement of Rational Internalism that adequately accounts for the common view that we necessarily motivated by the recognition of moral obligations