If
Sam Harris and
Robert Sapolsky are to be believed, our wills are merely the result of what came before. Everything has a prior cause and our actions are inextricably linked to what preceded it and that which preceded that is also governed by what came before and so on until the
beginning of time.
Do our choices matter? Paradoxically, yes it still does since our actions also affects what will follow.
This is not to be mistaken for fatalism or an excuse to not make choices, which you will soon realize is in itself a choice.
Why point this out then? Well, Sapolsky seems to be suggesting that giving this idea some thought might lead us to a more humane way of dealing with each other. If your actions do not come from you alone then maybe we can be more forgiving of others when we are "wronged".
The implications are huge and far reaching. The justice system will have to be reconfigured. No one is suggesting we let harmful people free but that perhaps removing them from general population is done not to punish and hurt (for sweet revenge) but to find out what is wrong with those who harm others and see if they can be remedied, not unlike a car with bad brakes.
It is a deterministic universe, but chaos also persists, so while we are bound by what came before, we are also able to realistically dream up of different ways the universe might unfold and perhaps even enjoy our part in the play.