For several millennia, people have worried about whether or not they have free will. What exactly worries them? No single answer suffices. For centuries the driving issue was about God’s supposed omniscience. If God knew what we were going to do before we did it, in what sense were we free to do otherwise? Weren’t we just acting out our parts in a Divine Script? Were any of our so-called decisions real decisions? Even before belief in an omniscient God began to wane, science took over the threatening role. Democritus, the ancient Greek philosopher and proto-scientist, postulated that the world, including us, was made of tiny entities””atoms””and imagined that unless atoms sometimes, unpredictably and for no reason, interrupted their trajectories with a random swerve, we would be trapped in causal chains that reached back for eternity, robbing us of our power to initiate actions on our own.
Lucretius adopted this idea, and expressed it with such dazzling power in his Stoic masterpiece, De Rerum Natura, that ever since the rediscovery of that poem in the 15th century, it has structured the thinking of philosophers and scientists alike. This breathtaking anticipation of quantum mechanics and its sub-atomic particles jumping””independently of all prior causation””from one state to another, has been seen by many to clarify the problem and enunciate its solution in one fell swoop: to have free will is to be the beneficiary of “quantum indeterminism” somewhere deep in our brains. But others have seen that an agent with what amounts to an utterly unpredictable roulette wheel in the driver’s seat hardly qualifies as an agent who is responsible for the actions chosen. Does free will require indeterminism or not? Many philosophers are sure they know the answer (I among them), but it must be acknowledged that nothing approaching consensus has yet been reached.