Obviously we are able to make our own choices about many things. Hume thinks this is all there is to talk of free will. If your action is caused by your choice and not by external factors (being hypnotized or coerced), then youf action is freely performed. But this is pretty minimal. Hume’s understanding of free will is quite compatible with your choice being fully determined by prior causes beyond your control (your genetic makeup, factors that have influenced you intellectually or psychologically, etc.). For this reason Hume’s understanding of free will is a “compatibilist” view, as it’s known in the free will literature. It’s a view on which having free will is compatible with causal determinism.
But compatibilism seems at odds with the intuitions many of us have about free will. Many want to hold that having free will means that you could have chosen differently even under the very same circumstances and the very same prior causal influences. That is, many would maintain that having free will is incompatible with your actions being causally determined. Descartes and Spinoza both had this more robust idea of free will in mind. On this more robust conception of free will, your will is in some way an un-caused cause of your actions. You cause you actions through your willing. But the way Descartes sees it, your willing is not itself caused (various factors may influence you in one way or another, but no combination of these determines your will).
This more robust idea of free will is also wrapped up in Christian religious thought. God is supposed to be just in rewarding the good and perhaps also punishing the bad. But it is hard to see how this could be just if we lacked free will in the more robust sense of our will being uncaused by factors beyond ourselves as agents. But there is something deeply puzzling about this. We have a hard time accepting that some things can just be so without there being some causal explanation for why they are so. Indeed this is a common reason for thinking there must be a God.
Note that this reason for thinking there is a God (there must be a cause) is quite at odds with Descartes’ pretty intuitive understanding of free will (your will is not causally determined). So it would seem that something has to give here. But then while this tension seems to undermine one line of argument for there being a God (if we are already committed to some things being uncaused, like our will, then why not allow that the world itself is uncaused as Spinoza does), it also helps to explain the sort of uncaused cause religious belief buys into. The only sort of uncaused cause that seems intuitively plausible to us is the action of the will. So if there must be something that causes things but is not itself caused, a God with a will like ours seems like a pretty good candidate.
Aristotle was the first to hold that the causal order requires that there be something to get the ball rolling, what he called an unmoved mover. Thomas Aquinas adapts this idea to an argument for the existence of God that still has strong appeal to many. But there remain deep mysteries here. We have no model or theory of “agency causation”. That is, we have no viable account to offer of how the will can be uncaused and yet caused. How would the action of such a will differ from just a roll of the dice (that would hardly be free will since here again the configuration of our will would not really be “up to us”.
And finally, our notion of causation is partly a temporal notion (as Hume will point out this week). But asking for causes of the universe in this sense stands in conflict with well settled physics (Einstien’s theory or relativity, in particular). We are rapidly closing in on a pretty clear understanding of the age of the universe. In fact just yesterday I attended a fascinating lecture on how the discovery of gravitational waves in just the past few years is helping us close in on a pretty precise age.
https://alumniandfriends.uchicago.edu/harper-lectures/spring2018/seattle
But this history of the universe is in part the history of time. What Einstien showed is that there is no absolute framework of time and space in which events unfold. Rather space/time comes into existence with the energy and matter of the universe. So our request for causes of the universe are just confused and misguided in light of Einstien’s discoveries. There just is no “before” in which to locate such a cause, supernatural or otherwise.
Oh, and by the way, BC has a recent hire in the physics department that has worked on the LIGO project detecting gravitational waves resulting from the collision of black holes. Fascinating stuff.