The view that acts cannot be responsible if they are caused has also been maintained by the advocate of ‘free will’, sometimes called the ‘Libertarian’. The Libertarian, like the Extreme Determinist, argues that if a person’s act is caused by his desire or by his character, and if these are caused by past events, then the true origin of his act is not in himself but in an infinitely remote past. But contrary to the Determinist, the Libertarian asserts that we are responsible for some of the things we do. Hence, he argues that we must have whatever conditions are required for responsibility; and the fundamental condition is that we have an ability to act differently. But he holds that this ability, since it escapes the chain of natural causes, is of a highly special sort. It is not what I have defined as an unrestricted ability to act, but is an ability ‘to will’ or ‘to choose’ or to do these things ‘freely’. In this chapter I shall consider the concept of willing, and in the next that of choosing, as each relates to responsibility.