This is the forty-first post in my Theories of Knowledge and Reality series. Follow the link for more on the series and for links to other entries as they appear. In the last post, I enumerated the main views that can be taken on the issues of freedom and determinism. Now I'd like to begin looking at arguments for and against the various positions.
In an earlier post in this series, I presented several arguments for thinking that we are free. Some people have taken those arguments as arguments that we have libertarian freedom. I don't see how they can be arguments for that. They might come alongside an argument that libertarian freedom is the only kind of freedom worthy of being called freedom. Then the whole package could support libertarianism. But those arguments don't come close to showing that we have libertarian freedom. A compatibilist could present the same arguments and say that they support thinking of ourselves as free. I'll return to this point in a couple posts when I look at some of the reasons people give for being compatibilists. I thought it was worth pointing out here because I want to make it clear that those aren't strictly speaking arguments for libertarianism but simply arguments for thinking we are free. Arguments for libertarianism don't conclude that we are free but that freedom is of a certain nature, and those arguments don't argue for any conception of what freedom is.
I do think the strongest arguments for libertarianism are actually arguments for incompatibilism combined with the conviction that we are free. So if incompatibilism is true, and we are free, then we must have a kind of freedom that isn't compatible with determinism. I won't try here to motivate any further the view that we are free, so nothing in the argument I'm about to present would be objectionable to the hard determinist, who accepts that incompatibilism is true but insists that we don't have freedom because we are predetermined. Assuming that we are free in some sense, as most people do, we now proceed to look at a reason some give for saying that we couldn't be free unless we had libertarian freedom (i.e. unless determinism is false).
I take this version of the argument largely from Peter van Inwagen, in particular from his book An Essay on Free Will and his chapter on freedom in the second edition of his Metaphysics book (which has a correction of a mistake found in both the first edition and the earlier free will book). These are probably among the best presentations of contemporary libertarian arguments that you can find. Some libertarians won't agree with van Inwagen on everything, but I think he follows arguments where they lead in a way that some libertarians seem a little squishier to me (but I'm open to finding that there is more hope for certain views than van Inwagen allows for; at this point I don't see it; more on that in the next post). So this post and the next one will be heavily dependent on van Inwagen's work on this subject.
The primary argument van Inwagen gives for incompatibilism is roughly as follows. Following Clifford Williams' term from his excellent little book Free Will and Determinism: a Dialogue, I usually call this the before-birth argument in my classes:
For any unchangeable fact p, if p ensures q, then q is an unchangeable fact. If there’s something that took place long before I existed, then it certainly qualifies as an unchangeable fact. If that determines everything about who I am, so that my desires and beliefs are all a product of that prior time, then how I am now is an unchangeable fact, and what determines my decisions now is an unchangeable fact. Why? If an unchangeable fact fully determined the way the world is now, and the way the world is now fully determines what I do, then what I’m now doing is an unchangeable fact.
This is why incompatibilists think freedom and determinism are incompatible, and a hard determinist basically agrees. We can look to compatibilists’ arguments to see if this argument is sound. For now, just understand the reasoning. Libertarians take this to be the commonsense view, one they thinks everyone believes anyway, and if that’s right then it shouldn’t take more argument than this to convince you, at least until compatibilists try to shift your allegiance their way. If there's no way I can change a fact that basically ensures that I do something, then I'm not free in doing that thing. Since determinism implies that there's nothing I can do to change things that affect what I do, and this is true of everything I do, then I'm not free if I'm predetermined.
This is main line of reasoning for incompatibilism, when combined with a conviction of being free, leads to libertarianism. In the next post I want to present a difficulty that libertarian views face, and then I'll look at reasons for compatibilism and how compatibilists try to get out of this argument. So while I'll move away from this argument for a little bit, I'll come back to it later on. I don't think it's really possible to do a fair treatment of the compatibilist response to this unless we have a good sense of why many philosophers find compatibilism plausible and libertarianism implausible. Those reasons are going to provide the compatibilist with the resources they will use to resist this argument.