According to A.J. Ayer's Freedom & Necessity, why does moral responsibility presuppose determinism?

Answer 1

According to Ayer, free will is only free if one's actions could have differed and because of ones actions he/she is held morally responsible. The person may have acted otherwise if the causes of his actions had been different. But being what they were it seems to follow that he was bound to act as he did. And if there is any causal determinism then there is no way for it to be free will, therefore presupposing determinism.

In fact, your first answer is wrong in the sense that Ayers held that free will and determinism are compatible. He slightly redefined both terms in order to achieve this position.

My additions: Moral responsibility is enacted upon us by society, but Ayer's theory doesn't seem to be able to justify it in human actions alone.

Answer 2

Aj Ayer Freedom And Necessity

Answer 3

Determinism is the complete absence of freedom. I doubt Ayer, a logical positivist, posited any such thing and you have not faithfully stated his position. Correct me if you can!