Hey,
In this post, I’d like to present a challenging area of applied ethics. Basically, social contracts are a kind of grease that makes the world go ‘round. When your acquaintance Barry says he will do something, in your planning for the future, you take it that soon what Barry will complete this task. If Barry breaks his promise to you, this can cause serious problems.

It seems that a utilitarian can’t see truth-telling as inherently valuable. Also, it seems that utilitarians can’t make totally binding promises. If a utilitarian believes it beneficial, he will offer a promise. But should you trust such a promise? Should a utilitarian include a disclaimer in all promises “I will break this promise if I feel it’s the right thing to do?”

I have an opinion of my own, but I would love to hear yours first!

I suppose the question is, "Why is the utilitarian making a promise?"
Presumably, he is doing so because the person to whom he is talking believes his action to be of greater necessity than the utilitarian [hereafter util] does. In which case, it's sensible for the util to accept, when he promises, that the action he guarantees to undertake is of more importance than he understands, and he ought to break this only if *extreme* new information comes to light. Plausibly he ought to add the disclaimer when promising "but I may break this promise if something major happens in the meanwhile" - but I think that last is presumed to be implicit whoever says it. If I promise to pick my friend Carla up from ice-skating on my way home from work and take her to her house, because she doesn't want to spend fifty quid on a taxi home, it is presumed that I will break the promise if my father has a heart attack and lies in hospital - I have no need to waste an hour driving her home. But utilitarianism merely helps me determine how important the new information is - as a trader, I believe in the rule that the market is generally right, and I can apply this here: my friend has more information than I do about how important my promise is to him, and therefore I should take his assumption as being correct.

I have no idea whether this is backed up by any utilitarian theory - it's just the best answer I can give offhand.

First of all, I don't think that utilitarianism per se applies so much to this situation, simple self interest does the trick.

If I make a promise, and break it, in the short term there may be benefits to me. In the long term, I have earned a reputation as a flake, which will mean that people will not trust me, will be more likely to flake on their promises to me, etc. So, from a purely selfish point of view, I should avoid doing so unless the benefits outweigh the negatives.

Even in situations where the repercussions are less obvious (say I make a promise to someone I don't expect to ever see again), in the long term there may well be negatives. For instance, my friends may find out that my sense of ethics only applies when there are direct repercussions, so they again stop trusting me, thinking that I will stab them in the back when it seems to be in my interest to do so. Or I have to try to deceive them about how I treat strangers, which is extra work.

I could go on at length about how our concepts of right and wrong can all be explained by Darwinian self interest (even in cases where it is less than obvious), but that may be straying from utilitarianism.

I have found both of your responses so satisfactory that I don't feel I need to write much of my own.

rob wrote:Simple self interest does the trick.
If I make a promise, and break it, in the short term there may be benefits to me. In the long term, I have earned a reputation as a flake, which will mean that people will not trust me, will be more likely to flake on their promises to me, etc. So, from a purely selfish point of view, I should avoid doing so unless the benefits outweigh the negatives.

Even in situations where the repercussions are less obvious (say I make a promise to someone I don't expect to ever see again), in the long term there may well be negatives. For instance, my friends may find out that my sense of ethics only applies when there are direct repercussions, so they again stop trusting me, thinking that I will stab them in the back when it seems to be in my interest to do so. Or I have to try to deceive them about how I treat strangers, which is extra work.

I could go on at length about how our concepts of right and wrong can all be explained by Darwinian self interest (even in cases where it is less than obvious), but that may be straying from utilitarianism.

We don't limit discussion to utilitarianism here. But I couldn't agree more that the so called problems of utilitarian lying are more simply explained by considering selfish lying.

TraderJoe wrote: Plausibly he ought to add the disclaimer when promising "but I may break this promise if something major happens in the meanwhile" - but I think that last is presumed to be implicit whoever says it. If I promise to pick my friend Carla up from ice-skating on my way home from work and take her to her house, because she doesn't want to spend fifty quid on a taxi home, it is presumed that I will break the promise if my father has a heart attack and lies in hospital

Yeah I think this is just the icing on the cake. Deontologists lie. When they want to break a promise, they cite extenuating circumstances. They fudge their rules with vague specifications so that they more closely approximate intuition. They say "do not lie unless something important comes up". Then they tell themselves that they're still doing deontology which is a lie too.