Before revision: Frankfurt's objection From the PAP definition "a person is morally responsible for what he has done only if he could have done otherwise", Frankfurt infers that a person is not morally responsible for what he has done if he could not have done otherwise – a point with which he takes issue: our theoretical ability to do otherwise, he says, does not necessarily make it possible for us to do otherwise.
After revision: Frankfurt's objection From the PAP definition "a person is morally responsible for what they have done only if they could have done otherwise", Frankfurt infers that a person is not morally responsible for what they have done if they could not have done otherwise – a point with which he takes issue: our theoretical ability to do otherwise, he says, does not necessarily make it possible for us to do otherwise.