 This highlights the real difficulty Frankfurt’s view faces in light of the Source Incompatibilist Argument. Since Frankfurt holds that what matters for moral responsibility is the relationship between an agent’s effective first-order desire and her second-order volition, and not the source of those respective desires, he is committed to thinking that even if the desires are implanted by some alien force, the agent can still be responsible for acting on them. But many have found it dubious that an agent could be responsible for an action that flows from motives that can be traced back to forces outside of the agent. In response, Frankfurt must show that being the source of one’s motives is not needed for moral responsibility. If he cannot, then it seems that the source incompatibilist has the upper hand. She can straightforwardly argue that, if one sort alien causal history that gives rise to the Frankfurtian mesh undermines agents’ freedom and responsibility, then why wouldn’t a deterministic history do the same?