Abstract. This paper examines two views of free will. It looks first at the fourteenth-century religious insights of John Duns Scotus, one of history's seminal thinkers about free will. It then examines what current neuroscience tells us about free will. Finally, it summarizes the past and present views and concludes by answering two questions: Does free will refer to an absence of external constraint, or does it refer to a human ability to decide in an acausal manner?