Reading over this post, I think the main thrust of my argument is that you should be able to see what is wrong with act utilitarianism if you have a sociological imagination. What if everyone justified their decisions in such a way without the guardrails imposed by considerations of human rights nor the signposts from various traditional values such as honesty, fairness, and so forth (that we can yet evaluate and reevaluate if they look like they might cause harm in some cases or indeed in every case for some of the more controversial traditions)? Even if done perfectly, it can have bad results. And if done imperfectly, it can be horrible. So we can say that in the long term, act utilitarianism seems like it fails based on its own foundational principle. It is not the best way to pursue utility.
I see zero reason those guardrails cannot still exist for an act utilitarian. Why would they not come into play as factors considered by the individual? Rule utilitarians do not have a monopoly on the concept of broad moral principles.
An act calculation might give rise to a reevaluation of a rule, but it has hardly 'taken precedence'. E.g. abortion: it is better to say that anyone should be able to have an abortion than to evaluate each abortion for its effect on utility and allow or disallow on that basis.
If an act calculation has given rise to an exception, then that's an acknowledgement that the rule was not appropriate for the situation. If the rule is reevaluated in such a way as to carve out exceptions, it edges further away from being a rule and further towards being a description for a series of act calculations. A rule is only a rule if it disregards circumstance at least most of the time.
That is not to say that one should not consider the consequences of their actions, only that they needn't be reconsidering the morality of theft every time they visit a relative.
This description of what an act utilitarian does is sort of absurd. Like saying someone who believes in the scientific method must actively reevaluate thermodynamics every time they eat or walk down the street. We can still have functional thought processes.
It is if you're operating from first principles every time and want to do it honestly and optimally. Act utilitarianism demands not just that you consider consequences but that you do the best thing as far as you can tell. Ironically, that perfectionism itself makes it more prone to serious error; there are situations that are rather uncontroversially acceptable. But what if, by sacrificing some principle or value or even person(s), you might do better than just acceptable? What if the "hard choice" is really the right thing to do? The rule utilitarian will tend to reject these unless given a very good reason not to do so, whereas the act utilitarian will be tempted-- especially if the 'sacrifice' is not something important to them but the benefit is. The result may be an atrocity.
So the rule utilitarian will tend towards complacency and protection of the status quo. Upheaval and violence are bad as a rule, so confronting oppressive authority is also always bad. We must not evaluate on a case by case basis, lest we make an error, after all.
That is not to say rule utilitarians are not capable of the same, but they have some handy signposts warning them of the danger ("Maybe don't do atrocities, it's probably going to be bad"). The act utilitarian only has the abstract principle of utility which oughtto lead them in the right direction, you would think, but easily may not because it is to be considered in its purest (and vaguest) form.
Everyone has those signposts and is free to consider broad principles. And act / rule utilitarians are both subject to abstraction; the difference being rule utilitarians will
extrapolate the conclusions of those abstractions much more broadly and without individual regard. If anything that's a much greater danger of abstraction; the propensity for it to bulldoze over the reality.
Act utilitarians can find themselves justifying torture, for example, in certain specific cases, like to get information that will stop some plot to bomb lots of people. Rule utilitarians are more likely to notice that being able to do torture effectively enough that it would reliably give the desired result in such a case-- getting the information required to stop the bomb plot-- requires expertise. And that expertise requires practice. And that practice means living in a society which tortures people somewhat regularly. Which is probably not the best approach to maximizing happiness and so forth-- just a guess.
You've just made an act calculation! Normalisation is also another factor literally anyone can take into account.
Say you live in a village. The village is terrorized by a dragon. It periodically eats the villagers or burns a building. Individually, none of the villagers can solve the problem of the dragon-- adventurism is not effective. Collectively, they may be able to stop the dragon in some way. But they are disunited and afraid and the dragon seems to target the houses of those that are not as obsequious. At any given time, the villagers have a number of options on how to spend their time over and above doing what they need to survive. For example, they can try to cheer up the families of those who have lost someone to the dragon. They can work hard and produce food and have lots of sex in order to have babies to replace those lost to the dragon (this might otherwise be phrased as "they can be good livestock"). They can pretend that there is nothing to be done about the dragon except learning how best to cope with it. They could also try organizing themselves to solve the problem of the dragon-- this will not have any benefits to utility until the problem is actually solved; the dragon decisively dealt with in some manner. Such organizing is hard. It involves many steps and risks; getting enough people on board, figuring out what to do once they are. This takes time which could be spent doing anything else. And then there is the possibility of reprisal. The utility function for these villagers is going to have local maxima in which the effects of the dragon's violence are mitigated but the dragon itself remains unchallenged; attempting to make progress on solving the problem comes at the expense of utility and will only have benefits assuming a particular series of events follows in which others also make choices which move away from the local maxima of the utility function. So no proper act utilitarian calculation is going to tell the villagers to organize themselves to solve the problem of the dragon; they will instead be directed to the best way in the short term to suffer its periodic killing and destruction but never to stop it. The status quo is maintained.
I have no idea why you've decided that act calculations would come to such a conclusion. You've added very strange moral weightings in order to push the hypothetical conclusion in that direction-- short term over long term, risk aversion, etc. An act utilitarian can absolutely conclude that the long term outweighs the short term, or that the risk is justified.
It's a rule utilitarian who is likelier to maintain the status quo in the face of oppression. Violence and murder are usually not the answer, so a rule would disregard the abominable situation they're in and apply that blanket approach. It's more than a little telling that in order to illustrate the benefits of rule utilitarianism, you've given an individual set of circumstances and come to an individual conclusion about what would be best-- an act calculation and categorically not the application of a rule.
But calculation is also prone to error. And power will justify itself using whatever tools are available. So you will see justifications of the kind, "yes, imperialism has some downsides but now India has railroads, so who can say really whether the British Empire was a good or bad thing?" Mill vacillated on his opinion of the colonial administration of India; but he was at least capable of thinking about it. Act utilitarians-- once it has started-- will take it as a given. Should it end? Well, gosh, that would be terribly disruptive. Rule utilitarians have a much easier time justifying human rights and avoiding (or at least recognizing) certain moral quandaries because in a funny way they have more time and reason to think about the finer details and grander possibilities. Or to put it another way, and quoting Mill in On Liberty they can "regard utility as the ultimate appeal on all ethical questions; but ... utility in the largest sense, grounded on the permanent interests of man as a progressive being" rather than a neat calculation for each individual case uninformed by the rest of them.
Of course, Empire was more often justified on broad sweeping generalisations than it was on individual effects. The impact on individuals was overlooked by supposed wider societal benefits-- circumstances overridden by ill-thought generalisations. Act utilitarians absolutely will not "take it as a given"-- constant evaluation and scepticism is core to the approach.
Also, "they have more time and reason to think about the finer details and grander possibilities"? What was it you said about hubris?
Rule utilitarians have the categorical imperative (and relevant modifications of it) in their toolkit. What would the world be like if everyone acted this way? What would the world be like if well-meaning people all acted in this way?
Questions that show their inadequacy upon a second glance. What would the world be like if everyone was a doctor or teacher? It would fall apart! Clearly becoming one is wrong as a rule.
Both of these questions are irrelevant to the act utilitarian. "What if we had a radically different economic system?" is not a question that should even occur to someone who is really an act utilitarian. Why dedicate any resources to pursuing that when you can donate all your money to Oxfam and volunteering at the soup kitchen? Do both? But that is bad to the extent that you're wasting time and other resources on revolutionary self-education and organizing which, let's face it, is probably not going to come to fruition any sooner or later (or at all) based on the actions of just you. But if everyone thinks that way, nothing will ever change-- at least, not in that direction.
You've made an act calculation here (with your own personal weightings, and seemingly designed to fail), produced a conclusion you don't like, and assumed everyone else would come to the same one.
These questions occur to anyone (and can be evaluated by anyone) with a somewhat transgressive or challenging outlook. Rule utilitarians do not have a monopoly on that.
An act utilitarian can weigh the long term benefits and risks and come to different conclusions. A rule utilitarian would approach the question, "what if we had a radically different system", without looking at the circumstances or merits of the cases-- and must apply their conclusions equally to Bourbon France and to socialist Cuba. If overthrowing one is good, then overthrowing both must be! And if overthrowing one is bad, we should overthrow neither!
