There is a long history of thought and research in the social sciences that views human beings as engaged in entirely instrumental activities in pursuit of goals that typically give them pleasure. This view makes a sharp distinction between “means” and “ends,” and treats the relation between means and ends as essentially arbitrary. Forty years of research on “intrinsic motivation” presents a different view, suggesting that some activities are themselves ends. In this chapter, we argue that distinguishing between intrinsic and extrinsic motivation has been important, but that the current understanding of the distinction is not adequate to capture the most important dimensions of difference between these two types of motives. We suggest a modification of the distinction, between activities that are pursued for consequences that bear an intimate relation to the activities themselves, and those that are purely instrumental. We call the former class of activities “internally motivated,” and argue that while they are not necessarily pleasurable, they yield lasting effects on well-being that instrumental consequences typically do not. Further, we argue that internally motivated activities differ from intrinsically motivated ones, in which the sheer pleasure of the activity motivates its pursuit. We discuss evidence from both laboratory research and field studies, including a longitudinal study of West Point cadets, in support of our arguments.