Abstract: This book presents the first detailed account of the discussion of the free will problem in British philosophy in the ‘long’ eighteenth century, beginning with Locke and ending with Dugald Stewart. In this period, the question of the nature of human freedom is posed principally in terms of the influence of motives upon the will. On the libertarian side of the debate are those who believe we are free in our choices. A motive, these philosophers hold, is a reason to act in a particular way, but it is up to the agent which motive he acts upon. On the necessitarian side of the debate are those who believe that there is and can be no such thing as freedom of choice. According to these philosophers, there will usually be one motive that is stronger than any other and that determines choice and action. Among the issues raised in eighteenth-century discussion of this issue are the nature of motives, the place of ‘indifference’ in an analysis of free will, the tenability of a distinction between ‘moral’ and ‘physical’ necessity, the relation between the understanding and the will, and internal coherence of the concept of freedom of will. James Harris places this debate in the context of the eighteenth-century concern by introducing the methods of ‘experimental’ inquiry into the philosophy of mind, and shows that at no point in this period is it uncontroversial that necessitarianism is the natural concomitant of a ‘scientific’ approach to human choice and action.

Keywords: free will, choice, motives, liberty, libertarianism, necessity, necessitarianism, experimental philosophy, consciousness, eighteenth-century