Will is the power to choose and act. Someone’s will is free if he isn’t causally determined to choose and act as he does. This kind of freedom is called “libertarian” (not to be confused with libertarianism the political philosophy!). Libertarian freedom is freedom proper, within philosophical discourse at any rate, and is to be contrasted with other kinds of freedom, improperly so called, such as voluntariness. A choice or an act is done voluntarily if the person who does it isn’t “dragged kicking and screaming”. To illustrate the difference between the two, imagine someone points a gun to your head and tells you to choose Cheerios for breakfast tomorrow or they’ll blow your brains out. You comply. Your choice of Cheerios is involuntary but still free in the libertarian sense, since you weren’t causally determined to choose Cheerios like a pre-programmed machine or billiard ball struck by a cue.

Do we have free will? The only proper sense of this question and the only version worth asking is, do we have libertarian free will? We must. This is a pragmatic “must”. If we don’t, then we might as well all become farmers (to quote one of my favorite philosophers). It would make life absurd and unlivable. Nothing we think, believe, say, or do would matter. We would cease to be persons, reduced to mere automata. We would cease to be rational: if you were determined by factors outside your control to believe, say, that the Earth is round, then how could that belief be rational? This would apply to all your beliefs, by the way, including any belief you may have that determinism is true, making determinism incapable of being rationally affirmed. But never mind all that. We must have free will because our existence depends on it. This doesn’t prove we have it, of course. But if in fact we don’t have it, who cares?