I've been struggling with this idea myself, but along these lines:<p>1. All events we know of are either caused by other preceding events, or are random.<p>2. One could reasonably claim that <i>all</i> events can ultimately be traced through their causal lineage to a random event, be it a random motion of a particle, the primordial quantum fluctuation that led to the universe, or subsequent fluctuations that broke the "smoothness" (symmetry) of the expanding universe and gave it detail.<p>3. For free will to exist, we have to posit another primary origin of events -- we don't know whether it's a particle, a field or some other entity and we can apply whatever label we want to it, but it will necessarily be another primary origin of events alongside random fluctuations.<p>4. If we disallow (3) as too "spooky", then what we're left with is the idea that what we perceive as free will and/or consciousness is an epiphenomenon that arises around randomness, especially randomness in large complex structures of connected, interacting nodes such as neurons.