My recollection from some extracurricular study of Schopenhauer in college is that he <i>rejects</i> Kant's metaphysical libertarianism. We can't transport the self across the division between the phenomenal and the noumenal, so even if we can exert that free will exists, we don't have epistemic grounds for meaningfully identifying ourselves with the thing in itself which we can assert has free will.<p>It's been a long time, though. Maybe it's time to reread and then pick up this book!<p>For those interested, the two source texts to consider in light of this book if you don't want to dig too deep, Kant's Prolegomena to Any Future Metaphysics and Schopenhauer's The World as Will and Representation are both public domain and relatively accessible/clear for the subject matter.