 This disagreement is conventionally understood to be driven by diverging approaches to the explanation of intentional action. Internalists are impressed by the differences between intentions and the cognitive states that figure in paradigmatic examples of theoretical reasoning. Pointing to these differences, they ask how practical reason can succeed in producing new intentions if it is not based in something of the same basic psychological type: a motivation or desire that is already part of the agent’s subjective motivational equipment. Many externalists find this contrast between intentions and cognitive states overdrawn.  They observe that we need to postulate basic dispositions of normative responsiveness to account for the capacity of theoretical reflection about reasons to affect our beliefs, and question why these same dispositions cannot explain the fact that practical reasoning is practical in its consequences. Cognitive or not, intentions belong to the broad class of attitudes that are sensitive to judgments, and this may account for the capacity of practical reflection to generate new intentions (Scanlon 1998, chap. 1). A third possibility is that intentions result from dispositions or capacities distinct from the psychic mechanisms that render theoretical rationality possible. Depending on how it is developed, this approach may offer a different way of accounting for the practical consequences of practical reflection, without assuming that reasons for action are grounded in an agent’s subjective motivations (Velleman 2000, chap. 8, Wallace 1999). 