 Start with the first horn and stipulate that Pro-R is a deterministic cause of Jones’ subsequent choice. But to prevent the libertarian from objecting immediately, let us suppose that Jones’ responsibility for his choice is not clear; indeed, we can suppose—even if initially shocking to Frankfurt’s allies—that he’s not responsible for it. Nevertheless, his being blameless is not due to something, namely Black and his device, that rules out alternatives. In the actual scenario, Black remains passive, merely monitoring Jones’ brain without interfering. The central idea here is that any factor causally isolated from an agent cannot be relevant to that person’s moral responsibility. So even if Jones isn’t responsible, this isn’t entailed by his lacking alternatives; this would be enough to refute PAP. (Fischer 1999: 113; cp. Frankfurt 2003. This is just a first pass at what turns out to be a much more complex argument. For further refinement and criticism, see Goetz 2005; Fischer 2010; Widerker &amp; Goetz 2013; Fischer 2013; Palmer 2014.)