Abstract

In this dissertation, I take the first steps toward arguing that the internalist thesis is implausible by examining the possible views of practical deliberation and the moral agent open to Humean internalists. According to motive internalism, there is a necessary connection between the making or truth conditions of ethical or normative thought and motivation. According to the Humean view of motivation, beliefs and desires are fundamentally different entities that exemplify different properties. Beliefs cannot by themselves motivate, but affective states can. Given these vast differences, the presence of one does not guarantee the presence of the other. ;Debates between Humean internalists and their opponents often stall frustratingly because each relies on competing conceptions of the agent as practical deliberator . The plausibility of these views, then, will be determined not by formal considerations of the premises, but by examining the view of practical deliberation that underlies them. ;In arguing for their premises, Humean internalists draw on certain psychological claims and are then bound to adhere to these claims when constructing their moral views. But these same psychological claims bar them from offering an adequate account of the premises they endorse. If internalism is true, moral judgments must both justify and explain an agent's actions. Explanatory reasons and justificatory reasons must be identified with each other. If the Humean view of motivation is true, then a subjectivist view must be advocated. Only subjective reasons exist. But moral agents see a need for objective reasons in order to be motivated in the way internalists suggest they are. Moral judgments must have adequate justification in order to provide agents with a reason to adhere to them. And subjective reasons cannot provide adequate justification. The Humean internalist view is self-defeating. It is internally inconsistent. If internalism is correct, it must be the case that objectivism is true. If objectivism is untenable, then internalism must be false