One difference between consequentialism so understood and old-fashioned Utilitarianism is surely that under consequentialism "you can exculpate yourself from the actual consequences of the most disgraceful actions, so long as you can make out a case for not having foreseen them." This means that one problem with consequentialism is that it is, in a sense, not consequentialist enough. There is too much scope for failure of imagination (by way of excess or deficiency) to exculpate. Hence, to give some examples, I might not be responsible for killing an innocent man if I genuinely felt (i.e., imagined that I was) mortally threatened by him and did not foresee that he might pose no real threat to my life, and I might not be responsible for plunging a country into violent anarchy if I sincerely expected my invading troops to be greeted as liberators.Let us suppose that a man has a responsibility for the maintenance of some child. Therefore deliberately to withdraw support from it is a bad sort of thing for him to do. It would be bad for him to withdraw its maintenance because he didn't want to maintain it any longer; and also bad for him to withdraw it because by doing so he would, let us say, compel someone else to do something. (We may suppose for the sake of argument that compelling that person to do that thing is in itself quite admirable.) But now he has to choose between doing something disgraceful and going to prison; if he goes to prison, it will follow that he withdraws support from the child. By Sidgwick's doctrine, there is no difference in his responsibility for ceasing to maintain the child, between the case where he does it for its own sake or as a means to some other purpose, and when it happens as a foreseen and unavoidable consequence of his going to prison rather than do something disgraceful. It follows that he must weigh up the relative badness of withdrawing support from the child and of doing the disgraceful thing; and it may easily be that the disgraceful thing is in fact a less vicious action than intentionally withdrawing support from the child would be; if then the fact that withdrawing support from the child is a side effect of his going to prison does not make any difference to his responsibility, this consideration will incline him to do the disgraceful thing; which can still be pretty bad. And of course, once he has started to look at the matter in this light, the only reasonable thing for him to consider will be the consequences and not the intrinsic badness of this or that action. So that, given that he judges reasonably that no great harm will come of it, he can do a much more disgraceful thing than deliberately withdrawing support from the child. And if his calculations turn out in fact wrong, it will appear that he was not responsible for the consequences, because he did not foresee them. For in fact Sidgwick's thesis leads to its being quite impossible to estimate the badness of an action except in the light of expected consequences. But if so, then you must estimate the badness in the light of the consequences you expect; and so it will follow that you can exculpate yourself from the actual consequences of the most disgraceful actions, so long as you can make out a case for not having foreseen them. Whereas I should contend that a man is responsible for the bad consequences of his bad actions, but gets no credit for the good ones; and contrariwise is not responsible for the bad consequences of good actions.The denial of any distinction between foreseen and intended consequences, as far as responsibility is concerned, was not made by Sidgwick in developing any one "method of ethics"; he made this important move on behalf of everybody and just on its own account; and I think it plausible to suggest that this move on the part of Sidgwick explains the difference between old‑fashioned Utilitarianism and that consequentialism, as I name it, which marks him and every English academic moral philosopher since him. By it, the kind of consideration which would formerly have been regarded as a temptation, the kind of consideration urged upon men by wives and flattering friends, was given a status by moral philosophers in their theories.
Another difference is that in consequentialism "the kind of consideration which would formerly have been regarded as a temptation [...] was given a status by moral philosophers." We see this in the following quotation from Benny Morris:
Even the great American democracy could not have been created without the annihilation of the Indians. There are cases in which the overall, final good justifies harsh and cruel acts that are committed in the course of history.He is talking about Israel, but many people in the United States think something like this. Or they think that the annihilation never happened, or it wasn't so bad because those were different times, or it was bad but it's in the past and therefore irrelevant, or they don't think about it at all. Or all of the above. What matters is the evasion of responsibility, not how the evasion is achieved.
But I don't mean to single out Americans. The Khmer Rouge were consequentialists too. Consequentialism is bad, ubiquitous, and not well understood. Philosophers can at least address the last of these. As I see it (going solely by this passage, which is probably a mistake), consequentialism holds (or at least implies) that the goodness or badness of an action depends entirely on the consequences expected by the agent. Whether these consequences are foreseen or intended does not matter. The intrinsic goodness or badness of the action is also irrelevant. And for these reasons consequentialism is doubly bad.