 Consider how the new dispositionalism bears on so-called ‘Frankfurt cases.’ These are cases due to Frankfurt 1969, where an agent chooses to and performs some action A while at the same time there is some other action B such that, had the agent been about to choose B, an ‘intervener’ would have altered the agent’s brain so that the agent would have chosen, and performed, A instead. One question about such cases is whether the agent, in the actual sequence of events, had the ability to B. Frankfurt’s intuition, and that of most others, is that she did not. Given the further claim that the agent is nonetheless morally responsible for doing A, this case appears to be a counterexample to the what Frankfurt calls the Principle of Alternative Possibilities (PAP): an agent is morally responsible for Aing only if she had the ability to perform some action other than A.