Promising
A Socratic walk-through of promising — reasoned out one step at a time, not lectured.
The question we started with
THE QUESTION #Why can saying a few words create an obligation that did not exist a moment earlier?
Say six words — "I promise to be there Thursday" — and something in the world changes. A moment before, staying home was merely one option among others. A moment after, it is a wrong you would have to answer for. Nothing moved, nobody was injured by the sound. So where exactly did the obligation come from?
The tempting first answer is that a promise is a forceful announcement of an intention, and the puzzle dissolves. Test it. Tell me you intend to come and then change your mind, and you owe me at most a courtesy. Promise, and you owe me something else entirely. Whatever the words are doing, they are not merely reporting the state of your mind.
Reasoning it through
REASONING #Try the next natural answer: the obligation comes from the expectation you created. You led me to count on you, I arranged my day around it, and defeating a reliance you deliberately induced is a way of using me. That has real force — it is roughly T. M. Scanlon's account, and it needs no special moral machinery, just a general duty not to manipulate what people expect.
But push on it. Weather forecasts create expectations I plan around, and the forecaster wrongs me not at all when the rain comes. So it cannot be expectation as such. Scanlon's answer is that the promisor intends the assurance and knows it will be relied upon. Yet a difficulty remains, pressed hardest by Niko Kolodny and Jay Wallace: why did my words give you assurance in the first place? Presumably because you took me to be bound by them. If so, the assurance is downstream of the obligation, and cannot be what generates it.
Which suggests looking not at the two people but at the thing they are both standing inside. Hume noticed that "I promise" resembles no natural act of will at all — you cannot, by an inner effort, will a new obligation into being, any more than you can will yourself taller. He concluded that promising is an artifice: a convention that exists because creatures who cannot see each other's future intentions need some way to make agreements over time. John Searle put the same point in terms of constitutive rules. Inside the practice, uttering the standard form in the standard circumstances simply counts as undertaking — and outside it there is no such act at all, as there is no run outside cricket.
John Rawls drew the sharp consequence. If the practice defines the act, two questions come apart that we habitually run together: why have a practice of promising is answered by its usefulness, while why keep this promise is answered inside the practice, which does not offer recalculation as a move.
Now the case that makes all of this bite. You promise a dying friend, with no witnesses, to deliver his money to a wealthy relative. He dies. The relative does not need it. A hospital does. Nobody will ever know, no expectations survive — the promisee is dead — and a practice is not weakened by an act no one observes. Every consideration we have assembled falls away, and yet most people find they still owe something. W. D. Ross took such cases as evidence that fidelity is a basic duty in its own right.
Notice where that leaves us. The expectation account struggles because the expectation is gone. The practice account can say the obligation stands — at the cost of looking as though it protects the institution rather than anyone's interests. And an account that makes the duty basic explains the intuition by declining to explain it. The puzzle is not that we lack an answer; each answer pays for its strength somewhere else.
The analogy
THE ANALOGY #Think of a signature on a contract. The ink is not what binds you — ink binds nobody. The signature binds because there is a standing arrangement under which making that mark, in that place, counts as taking on a term, and everyone who deals with the arrangement relies on marks meaning that. The mark has no power of its own and complete power inside the practice.
A contract sits inside an enforcement system that can compel you, whereas a promise typically has no enforcer at all — which is precisely why the question of what binds you is live for promises and comparatively dull for contracts.
Clarifying the model
THE MODEL #Three refinements are worth holding on to.
"Convention" does not mean "arbitrary" or "optional". Hume's point is that the practice is invented, not that it is weightless; a convention solving a real coordination problem can generate obligations as unyielding as any.
The accounts are also not straightforwardly rivals. Most promises involve both a practice and an induced expectation, and they diverge only in the strange cases — the secret deathbed promise, the promise nobody relies on — which is why those cases carry so much argumentative weight.
And an old regress worry from H. A. Prichard sits under all of it. If promises bind because we have adopted a convention of being bound, what binds us to the convention? Answering "a further agreement" starts the problem again.
A picture of it
THE PICTURE #How to readRead down the page as time passing, from the moment of speaking to the moment of temptation. Steps 1 to 3 are the practice account: the words work only because a convention treats them as an undertaking. Steps 3 and 4 alone are the expectation account, which needs no practice in the middle. Steps 5 to 7 are the hard case: the recalculation that seems to change nothing, and the release that cannot be sought because the one person who could grant it is gone.
What became clearer
WHAT CLEARED #The words do not carry obligation the way a stone carries weight. They work because they are a move in a practice, or because they induce a reliance the speaker intended — and the two explanations agree almost everywhere and part company exactly where it matters. In the case where breaking the promise would plainly do more good and harm nobody, the obligation still seems to stand, and no account explains that without either protecting an institution for its own sake or declaring the duty basic and stopping. That is where the argument actually is.
Where to go next
ONWARD #- Whether a promise extracted by deception or made under duress binds at all, and what that reveals about the practice.
- How the same puzzle appears for consent, forgiveness, and apology — other acts that seem to change the moral situation by being performed.
Key terms
TERMS #| Term | What it means |
|---|---|
| Constitutive rule | a rule that does not regulate a pre-existing activity but creates it, as the rules of cricket create the act of scoring a run. |
| Practice conception of rules | Rawls's view that where an act is defined by a practice, the justification of the practice cannot be reused to justify departing from it. |
| Prima facie duty | Ross's term for a real duty that can be outweighed by another without ceasing to have been a duty. |
Every term the collection defines is gathered in the glossary.