I think you&#x27;re missing the point somewhat. Yes, Aaronson assumes that something like physicalism is true, which I think is fairly defensible as a 21st-century scientist. But the argument isn&#x27;t as simple as &quot;physicalism entails the absence of free will&quot;. His point is that even if our actions are (probabilistically) <i>determined</i> by a set of underlying physical laws, it may still be that the character of those laws is such that it is fundamentally impossible to <i>predict</i> future actions, in which case we would still have meaningful free will.<p>The main form of prediction-impossibility he mentions is that our minds might depend meaningfully on quantum states, which are governed by the no-cloning theorem and therefore impossible even in principle to extract. Whether or not this is true is an open question, but the characterization of free will in terms of the concrete question &quot;is it possible to build a prediction machine?&quot; seems like a useful and novel contribution that doesn&#x27;t just reduce to the old question of &quot;is physicalism true&quot;.