The Epistemic Principle of Alternative Possibilities

Abstract

In his seminal paper 'Alternate Possibilities and Moral Responsibility', Frankfurt argues against the Principle of Alternate Possibilities (PAP), according to which a person is morally responsible for what he has done only if he could have done otherwise. This paper argues that even if Frankfurt's attack on the PAP is successful, the role that alternate possibilities play in moral responsibility differs from the role assigned to them by the PAP. It proposes a new way of understanding the importance of alternate possibilities to moral responsibility by introducing an epistemic version of the PAP (the E-PAP). According to the E-PAP, a person is morally responsible for what he has done only if he knew that he could have done otherwise. It is the lack of alternative possibilities together with the person's justified belief in this fact which negate moral responsibility. After defining the E-PAP in detail, the paper illustrates how the E-PAP is immune to most kinds of Frankfurt-type examples. Furthermore, the E-PAP is also used to explain why, even if Frankfurt’s attack on the traditional PAP is successful, incompatibilists may still continue to hold that determinism threatens the very possibility of moral responsibility.