Traditionally, incompatibilism has rested on two theses. First, the familiar Principle of Alternative Possibilities says that we cannot be morally responsible for what we do unless we could have done otherwise. Accepting this principle, incompatibilists have then argued that there is no room for such alternative possibilities in a deterministic world. Recently, however, a number of philosophers have argued that incompatibilism about moral responsibility can be defended independently of these traditional theses (Ginet 2005: 604-8; McKenna 2001; Stump 1999: 322-4, 2000 and 2002; van Inwagen 1983: 182-8; and Zagzebski 2000). Incompatibilists of this stripe are generally motivated by the concern that, if determinism is true, we are not genuine or ultimate sources of our actions and, hence, we are not responsible for what we do. Following Michael McKenna (2001), I shall call this view source incompatibilism. While the source incompatibilist's concern is rather vague as stated, it has given rise to a powerful argument against any attempt to reconcile moral responsibility and determinism. John Martin Fischer and Mark Ravizza (1998) have labeled this the Direct Argument, as it avoids the detour of alternative possibilities.
Understanding Source Incompatibilism
