To save our belief in the freedom of will from the fateful grasps of Cause and Chance, people simply postulate an empty, third alternative. We imagine that somewhere in each person's mind, there lies a Spirit, Will, or Soul, so well concealed that it can elude the reach of any law — or lawless accident.
I've drawn the box for Will so small because we're always taking things out of it — and scarcely ever putting things in! This is because whenever we find some scrap of order in the world, we have to attribute it to Cause — and whenever things seem to obey no laws at all, we attribute that to Chance. This means that the dominion controlled by Will can only hold what, up to now, we don't yet understand. In ancient times, that realm was huge, when every planet had its god, and every storm or animal did manifest some spirit's wish. But now for many centuries, we've had to watch that empire shrink.
Does this mean that we must embrace the modern scientific view and put aside the ancient myth of voluntary choice? No. We can't do that: too much of what we think and do revolves around those old beliefs. Consider how our social lives depend upon the notion of responsibility and how little that idea would mean without our belief that personal actions are voluntary. Without that belief, no praise or shame could accrue to actions that were caused by Cause, nor could we assign any credit or blame to deeds that came about by Chance. What could we make our children learn if neither they nor we perceived some fault or virtue anywhere? We also use the idea of freedom of will to justify our judgments about good and evil. A person can entertain a selfish impulse, yet turn it aside because it seems wrong, and that must happen when some self-ideal has intervened to overrule another goal. We can feel virtuous when we think that we ourselves have chosen to resist an evil temptation. But if we suspected that such choices were not made freely, but by the interference of some hidden agency, we might very well resent that interference. Then we might become impelled to try to wreck the precious value-schemes that underlie our personalities or become depressed about the futility of a predestination tempered only by uncertainty. Such thoughts must be suppressed.
No matter that the physical world provides no room for freedom of will: that concept is essential to our models of the mental realm. Too much of our psychology is based on it for us to ever give it up. We're virtually forced to maintain that belief, even though we know it's false — except, of course, when we're inspired to find the flaws in all our beliefs, whatever may be the consequence to cheerfulness and mental peace.