Some theorists have argued that we should understand the notion of free will from a functional perspective: free will just is our ability to choose effectively and adaptively in an ever-changing environment. Although far from what many philosophers normally mean by free will, those who adopt this biological-evolutionary perspective can clearly define and defend a notion of personal responsibility. One consequenceof this point of view is that addicts become responsible for their actions, for at each choice point, there is a (...) real sense in which the addict could have elected not to use or abuse. As a result, it has been argued that addiction is not a disease, that addictive behavior is voluntary, and that sometimes it is even rational. This paper defends a different way of thinking about addiction, one that aligns it with other complex chronic illnesses. The perspective put forth here suggests that these discussions about responsibility and free will represent an over-simplified and neuropsychologically inaccurate portrait of basic human capacities for behavioral choice. (shrink)