Everything that happens in the universe (and our
minds) depends on some combination of two things:
There is no
middle ground. This is awkward for us as individuals who think of and speak of
volition,
will, and
self-control. Few people will make the statement "My choice was wholly determined by internal and external forces I do not understand", however accurate it is.
Each one of our actions comes from a series of processes that take place within our minds. Some of them we happen to understand, but these are the small minority of what goes on.
But without free will, much of what is part of us and our society seems to crumble. Where is the place of praise and punishment when the action was a result of chance or something that was determined to be. It is free will that forms part of the judgment of good and evil. We feel virtue when resisting an evil temptation, but how much of that is our choice?
Through childhood we learn about various forms of coercion and compulsion and resent it when people use them to influence us. We as thinking beings want to make our own choices, even as a child. It is difficult for us to accept something that we cannot control being held as 'responsible' for all of our actions. There are more than a few people who become depressed about the futility of a universe of predetermination which is tempered only by chance.
The illusion of free will is an essential part of who we are as humans. The notions of responsibility, good and evil, self control and volition. Justice and punishment are closely linked to the question of free will - who are we to punish people who were destined to do as they did.