Phil 101: Intro to Free Will (Part 1 of 2)

Free Will and Worries about It

Our topic will be the kind of thing we talk about when we say that someone “has (or exercised) free will,” or “made a free choice,” or “acted freely.”

To try to get clearer on whether we have free will, we need at the same time to try to get clear on what free will is, or would be if anyone had it. It’s not so easy to do that. Many of the ways people will explain what they mean by “free will” are either uninformative, or else render the question of whether we have free will uninteresting. For instance, if we define “free will” as “having the power to do what you want to do,” this is not very informative: for the notion of “having the power to do something” is too similar to the notion we’re trying to explain. (If someone had philosophical perplexities about what free will was, they’d also have perplexities about what it is to have the power to do something.) We’d like to get a more informative understanding or explanation of what free will is than that.

Worries about whether we have free will arise from several different sources.

One sort of worry starts from the premise that the laws of nature and the past “causally determine” that you will act in the way you do. (More on what this means below.) This is thought to show that you’re not free to act in other ways. This worry concerns the relation between free will and Determinism.

A second sort of worry starts from the premise that there is only one “real” future. Perhaps someone already knows how this future will turn out. (For example, perhaps God knows this. Or perhaps some oracle with a crystal ball knows this, or a time traveller who’s come here from the future. Or perhaps we already have a problem if future historians looking back on the present day will know how things turn out.)

Or perhaps the trouble doesn’t depend on anyone knowing how the future will turn out. Even if no one now knows or is able to predict how you will act tomorrow, maybe there’s already some truth about how you will in fact act tomorrow. And if you will in fact act in certain ways tomorrow, it seems to be already true today that you will act in those ways tomorrow. This can seem like it also deprives of you of the freedom to act otherwise: what you’ll do tomorrow is inevitable, because it’s already true that you’ll act the ways you will. This is what’s called a fatalist worry.

We’re going to focus on the first sort of worry in our course (and these notes).

For both kinds of worry, one way to respond to them is to deny their respective premises. That is, we might deny that the laws of nature and the past causally determine your actions; and we might deny that claims about what you will do tomorrow are already true today.

Another way to respond to these worries is to concede the premises (perhaps only for the sake of argument), but to argue that no dire conclusions about free will follow from these premises.

Free Will and Determinism

What is Determinism? This thesis is defined in different ways. Sometimes it’s understood to be the thesis that how the future will be is entirely predictable from how the past was. Other times it’s understood to be the thesis that every event has a cause. (That’s how Clifford Williams defines it in the dialogue we’re reading, see p. 3.) However, for various reasons (some of which I’ll mention later in class), neither of those definitions really captures the core idea that’s most at issue in contemporary philosophical debates about free will.

For our purposes, the best way to define Determinism is instead as follows.

Certain laws of nature are such that, for a given “starting point” for the universe, those laws are compatible with only one subsequent future. Any world with that past but a different future would violate those laws. It couldn’t be a world that those laws described or governed. We call laws of this sort deterministic laws. Given a starting point, these sorts of laws require the future to proceed in a single fixed way. Any two possible worlds, if they started off the same way, and both had the same deterministic laws, must continue in the same way.

Other laws of nature are compatible with more than one subsequent future. We call these indeterministic laws. These laws may say: given this starting point, the world can evolve in any of ways A, B, or C. None of these possible futures is guaranteed to happen.

We will understand Causal Determinism, or Determinism for short, to be the thesis that all of the laws of nature that govern our world are deterministic laws.

Is Determinism true? This has been disputed for a long time. Some of the ancient Greeks, especially the Stoics, thought that it was. The “clockwork” picture of the universe we get from Newton is also a Determinist one. In more recent physics, things are less clear. Our best theories of quantum physics are not obviously deterministic. They don’t say “in situations like this, so-and-so is guaranteed to happen.” Instead they involve probabilities in ways we can’t eliminate. However, it is philosophically controversial how the probabilities in those theories should be interpreted. Hence, one cannot easily say whether or not our best theories of quantum physics posit that our world has indeterministic laws.

We’ll take this issue up next time.