Lin and Xu shared a flat when they were young. They eventually married and moved into separate homes, but kept meeting for lunch on the first Saturday of each month. For twenty years nobody formally proposed this arrangement. The date came around; one of them walked into the restaurant; the other was already there.

When Xu’s father went into hospital, Lin offered to deliver his meals every day for a month. Xu then accepted a full schedule of shifts at work. A sentence had become part of a rota, and part of the hospital’s daily life.

But pause the story before Xu changes his schedule. Lin has just spoken. Nobody has relied on him yet. Does his promise already matter? If its force came entirely from reliance, it would have no weight at this moment. Yet making a promise is not usually like mentioning tomorrow’s weather. Something has happened on the speaker’s side too.

Lin has taken a stand: this is something he undertakes to do. While he continues to stand there, he cannot both maintain that undertaking and treat it as if it never existed. An emergency may prevent him from delivering a meal. It does not retroactively remove the promise from the situation he must face.

This need not require constant attention. A promise does not expire whenever its maker sleeps, forgets it for an afternoon, or fails to issue a fresh declaration. What persists is the undertaking, unless it is changed or left. What cannot be supplied in advance is tomorrow’s act: the person who wakes up tomorrow still has to perform it.

What was said, what still stands, what remains

Three questions help here. What did someone actually say or do? Do they still stand behind it, and what have they revised? What effects has it already had in another person’s life? These questions belong together, but no one of them answers the other two.

Xu can remember the offer or produce the message in which it was made. Lin’s later denial cannot make that evidence disappear. Evidence of the words, however, does not give an observer direct access to Lin’s sincerity at the time, or to the way he understands his change of mind now.

Suppose a meal fails to arrive. Was Lin ill? Had the two friends agreed that somebody else would go? Did he simply not turn up? Those are different accounts of what happened. One missed visit cannot by itself establish that the original offer was a lie. Equally, Lin’s assurance that he remains committed cannot turn an undelivered meal into a delivered one.

The third question is where Xu’s rota comes back in. If Lin changes his mind, Xu’s shifts do not rearrange themselves. Somebody must face the missing meals, the alternative arrangements, any delay already caused. Lin cannot do this merely by announcing that he no longer wishes to continue.

These effects are not a neatly calculable debt, nor do they automatically require him to remain indefinitely, restore every channel of contact, or keep answering without limit. They are real effects that his departure does not settle. Saying that he can leave and saying that nothing remains are quite different claims.

Revision also differs from quietly dropping something when it becomes inconvenient. A revision can acknowledge the former undertaking, what changed, and what has been left behind. Dropping it tries to make the earlier stand disappear from the account. Much of that difference is known from within. From outside, we can report failures, obstacles and agreed changes, ask questions, and make fallible inferences. We should hesitate before turning one failure into a final description of a person.

In this account, a personal promise is not an obligation owed to its recipient. Its force lies in what the speaker genuinely continues to undertake and in effects already left in another person’s life. That is a choice about where binding force comes from, not a demonstration that every theory of directed obligation is false. Nor is it an interpretation of contracts, legal duties or the responsibilities of an office. It offers no convenient excuse for unreliability: the maker cannot escape the past by merely declaring the future different.

Twenty years cannot sign for someone

Eventually Xu moves to another city. He phones Lin: the monthly lunches may no longer be possible. Lin feels an absence opening in his calendar. Twenty years do not vanish because someone crosses out a recurring appointment. The table, the restaurant and the spare Saturday have become part of his life.

Does this prove that Xu promised, twenty years earlier, to attend forever? No. An unspoken commitment can certainly exist, and can grow gradually. But repetition alone cannot establish it. Xu may have freely chosen each lunch without having undertaken all the lunches still to come.

We need not banish the word understanding from friendship. How the friends handle a missed date, give notice, make room for a work trip, or arrange the next meeting all provide material for describing an implicit commitment. The description remains answerable to what each person actually undertakes. ‘We seem to have made this part of our lives’ is not the same as ‘You have always done it, so I can declare that you promised.’

Nor does uncertainty about a promise make Lin’s loss imaginary. The reliance built over twenty years is real. Xu’s departure does not erase it. But acknowledging that history is different from granting Lin permanent authority to summon him back. A relationship can have consequences without those consequences becoming ownership.

Consider a smaller variation. Lin decides to stop smoking and tells Xu. Xu stops offering him cigarettes. Has a promise to himself now become a promise to his friend? Not necessarily. Reporting an intention is not always undertaking something for the listener. If Lin later revises his decision, he should not pretend Xu never heard about it or made any arrangements. Those are effects of telling him. They do not, by themselves, establish a promise made to Xu.

For an undertaking that concerns only oneself, a later revision which honestly acknowledges the earlier decision can complete the revision. Where a promise has been made to another person, changing one’s own position cannot also settle that other person’s side. The difference is not between serious and disposable promises. It is between what remains in the two situations.

Staying is not the same as being kept

We often praise a relationship for lasting. Duration deserves another question: what is keeping each person there? One may still stand behind a promise. Another may make no general promise but freely choose to continue. Someone else may be unable to leave, keep postponing a decision, or follow a habit whose original meaning has gone. From a distance, all these arrangements can look equally stable.

Time alone proves none of them. Nor does an observer’s uncertainty prove that neither person has a reason of their own. What began as delay can acquire a freely accepted basis; a freely accepted practice can gradually hollow into inertia. This is not a prediction that certain relationships must collapse. It is a reason to look separately at each end instead of treating ‘the relationship’ as one satisfied person.

A promise cannot own tomorrow. In practice, however, people can make tomorrow’s alternatives unreachable. Calling departure betrayal tries to settle what another person’s departure must mean. Threatening to ruin their livelihood adds pressure directed outward. Withholding identity papers, cutting off help, or imposing consequences that actually prevent escape goes further: it closes a basic way out. These acts cannot be justified simply by pointing to an old promise.

Not every increased difficulty is such an act. Someone withdrawing their own participation may leave me worse off without thereby blocking my departure. We must distinguish that loss from additional punishment or isolation that raises the cost of refusal, seeking help or leaving, perhaps to the point of making a way out inaccessible. Fear alone does not settle which structure is present; concrete circumstances matter.

Something comparable can happen in a promise to oneself. A firm decision to stop smoking may remain open to serious reconsideration. Or ‘I swore I would’ may become an answer that disqualifies every attempt even to ask. Feeling pressure is not yet being unable to revise. Conversely, a declaration that revision is permitted means little when there is no actual route to it.

Can someone still sincerely say, ‘I will never leave you’? Yes, as an expression of where they stand, not as a document signed on behalf of every future moment. A later change does not prove that earlier sincerity was fraudulent. But solemn words cannot simply be discarded after use; nor can their listener use them to shut the speaker back inside. The inability to guarantee forever does not empty a promise of weight. Its weight does not entitle it to possess every later part of a life.

Perhaps Xu will return for occasional lunches. Perhaps he will not. The meals Lin delivered were not made worthless by later change. What Xu once undertook was not made never to have happened. A promise has weight without being a padlock: while I stand behind it, I take it seriously; when I change or leave, I do not pretend that my steps have never passed through somebody else’s life.