Believing at will
A Socratic walk-through of believing at will — reasoned out one step at a time, not lectured.
The question we started with
THE QUESTION #Why can you decide to raise your arm but not decide to believe it is raining?
Raise your arm. Done, and nothing intervened between the deciding and the doing. Now, sitting in dry sunlight, decide to believe it is raining. Not pretend, not imagine, not say the words — believe it, the way you believe your own name.
You cannot. And the first thing to notice is that the failure is strange. It is not that the task is hard, as juggling is hard. It is not that you lack information. You are not even sure what you would try to do. The obvious diagnosis — that the evidence is against you — turns out not to survive a moment's inspection either, so the interesting question is what kind of impossibility this is.
Reasoning it through
REASONING #Take the evidence diagnosis first. Pick something the evidence is entirely silent about: the number of leaves on the tree outside is odd. You have no evidence either way, no stake, nothing to lose. Now decide to believe it. Still nothing happens. So the obstacle is not that evidence blocks you; it is present even where evidence is absent.
Look instead at what believing something is. To believe that it is raining is to hold it as true — to be set to act on it, to be surprised if it turns out otherwise, to take it as a premise for other things. Now suppose you could have brought that state about by deciding to. Then you would know something about your own belief: that its cause was your decision, and not anything about the weather.
Follow the consequence carefully, because it is the whole argument. Holding a proposition as true involves taking yourself to be tracking how things are. But you would know your state had been produced by an act with no connection to the rain. That knowledge does not sit alongside the belief — it dissolves it, in the way that being told a witness was paid dissolves the testimony rather than supplementing it. So the project defeats itself: to succeed, you would have to forget how you succeeded. This is essentially Bernard Williams's argument, and the striking feature is that it locates the obstacle in what belief is rather than in any weakness of ours.
Does that predict anything beyond the case we started with? It should predict a sharp boundary: the mental states you can produce at will are exactly the ones that do not claim to be true. And they are. You can imagine rain, suppose it for the sake of an argument, pretend it, accept it provisionally as a working assumption for a calculation. All are voluntary, all involve rain, and none of them assert anything. The moment a state's job is to be answerable to how things are, the will loses its grip on it — not a coincidence but the same fact stated twice.
Notice too that the arm side of the contrast is less special than it looks. Wanting is not fully voluntary either; you cannot decide to want a food you dislike. The clean division is not mind against body. It is truth-directed states against everything else.
The analogy
THE ANALOGY #Think of a measuring instrument with a dial you could reach in and turn by hand. Turning it is easy; the mechanism does not resist. But the moment you have turned it, the position of the needle is no longer a reading — it is a setting, and you know it. The instrument has not been made to say something; it has been taken out of the business of saying anything.
An instrument can be forced to a false position and left there, whereas you cannot even manage the first step, because a belief is not a component you observe from outside but the very perspective from which you are looking — there is no position you could stand in to turn your own dial and then trust the needle.
Clarifying the model
THE MODEL #Three refinements, and the second is the one people usually want.
The first is that this is only about direct voluntary control. Indirect control is real and unmysterious. You can choose what evidence to seek and what to avoid, whom to spend time among, what to rehearse, what to look at again. Pascal's advice to the doubter — act as the devout act, and belief will follow — is a proposal of exactly this kind, and it is not obviously wrong about human beings. Over years, people talk themselves into things. What nobody can do is the single deliberate act.
The second: the impossibility above is a conceptual claim, and it is contested. Some philosophers hold that the constraint is merely psychological — that a being constituted differently could believe on command — while others argue for a modest voluntarism, on the ground that we hold each other responsible for beliefs, blame people for credulity, and speak of making up one's mind, which would be odd if nothing there were up to us. A reasonable middle position is that belief formation is under our influence and answerable to our care without being under our command, which is enough to support responsibility without requiring the impossible act.
The third addresses the awkward case: people plainly do believe things because they want to. Motivated reasoning, wishful thinking and self-deception are ordinary. But look at how they work. None of them proceeds by deciding to believe. They proceed by lowering the standard of scrutiny, by attending selectively, by reinterpreting — and they require the person not to see themselves doing it. That the will's influence must be covert to work is not a counterexample to the argument; it is the argument's prediction.
A boundary worth marking. Whether any of your choices are genuinely yours, given that each has causes behind it, is a separate problem. This question takes ordinary voluntary action entirely for granted — the arm goes up, and that is not in dispute here — and asks only why belief is not among the things that can be done that way. You could be a thoroughgoing determinist or a thoroughgoing libertarian about the will and the answer here would not change.
A picture of it
THE PICTURE #How to readDrop each point to the horizontal axis to ask whether that state claims to represent how things are, and across to the vertical to ask whether you can produce it by deciding to. Everything voluntary sits on the left, among the states that assert nothing. Everything truth-directed sits low on the right, out of reach. The interesting region is the top right, which is empty: no state both aims at truth and answers to the will, and the argument above says the emptiness is structural rather than accidental.
What became clearer
WHAT CLEARED #You cannot believe at will not because the evidence forbids it and not because you are weak, but because a belief is a state whose whole point is to be answerable to something other than your choosing. Produce one by choice and you have knowingly produced a state whose cause is unrelated to its subject — which is not a belief, only a setting. The states you can summon are precisely those that make no claim about the world. The will still reaches belief, but only the long way round: through attention, company, and what you allow yourself to look at.
Where to go next
ONWARD #- Whether people can be blamed for their beliefs, if belief is not something they choose.
- How acceptance — taking a proposition as a working premise without believing it — functions in science and law.
Key terms
TERMS #| Term | What it means |
|---|---|
| Doxastic voluntarism | the view that beliefs can be formed by an act of will; direct versions are widely rejected, indirect versions widely accepted. |
| Constitutive aim of belief | the idea that a state counts as a belief only insofar as it is regulated by whether the proposition is true. |
| Acceptance | voluntarily taking a proposition as a premise for reasoning without holding it true. |
| Motivated reasoning | belief shaped by preference through selective attention rather than by decision. |
Every term the collection defines is gathered in the glossary.