As for morally, we must observe at once – again following Anscombe – that Plato and Aristotle, having no word for “moral,” could not even form a phrase equivalent to “morally right.” The Greek thik aret means “excellence of character,” not “moral virtue”; 2 Cicero's virtus moralis, from which the English phrase descends directly, is simply the Latin for thik aret. This is not the lexical fallacy; it is not just that the word ‘moral’ was missing. The whole idea of a special category called “the moral” was missing. Strictly speaking, the Aristotelian phrase ta thika is simply a generalizing substantive formed on th, “characteristic behaviors,” just as the Ciceronian moralia is formed on mores. To be fully correct – admittedly it would be a bit cumbersome – we should talk not of Aristotle's Nicomachean Ethics but of his Studies-of-our-characteristic-behaviors Edited-by-Nicomachus.

Plato and Aristotle were interested – especially Plato – in the question how the more stringent demands of a good disposition like justice or temperance or courage could be reasonable demands, demands that it made sense to obey even at extreme cost. It never occurred to them, as it naturally does to moderns, to suggest that these demands were to be obeyed simply because they were demands of a special, magically compulsive sort: moral demands.

Their answer was always that, to show that we have reason to obey the strong demands that can emerge from our good dispositions, we must show that what they demand is in some way a necessary means to or part of human well-being (eudaimonia). If it must be classified under the misconceived modern distinction between “the moral” and “the prudential,” this answer clearly falls into the prudential category. 4 When modern readers who have been brought up on our moral/ prudential distinction see Plato's and Aristotle's insistence on rooting the reasons that the virtues give us in the notion of well-being, they regularly classify both as “moral egoists.” But that is a misapplication to them of a distinction that they were right not to recognize. 

When we turn from the Greeks to Kant and the classical utilitarians, we may doubt whether they shared the modern interest in finding a neat definition of the “morally right” any more than Plato or Aristotle did. Kant proposed, at most, a necessary (not necessary and sufficient) condition on rationally permissible (not morally right5) action for an individual agent – and had even greater than his usual difficulty expressing this condition at all pithily. The utilitarians often were more interested in jurisprudence than in individual action, and where they addressed the latter – as J. S. Mill often does, but Bentham usually does not – tended, in the interests of long-term utility, to stick remarkably close to the deliverances of that version of “common-sense morality” that was recognized by high-minded Victorian liberals like themselves. When Kant and the utilitarians disagreed, it was not about the question “What are the necessary and sufficient conditions of morally right action?” They weren't even asking that question.

The terms "should" or "ought" or "needs" relate to good and bad: e.g. machinery needs oil, or should or ought to be oiled, in that running without oil is bad for it, or it runs badly without oil. According to this conception, of course, "should" and "ought" are not used in a special "moral" sense when one says that a man should not bilk. (In Aristotle's sense of the term "moral" [...], they are being used in connection with a moral subject-matter: namely that of human passions and (non-technical) actions.) But they have now acquired a special so-called "moral" sense — i.e. a sense in which they imply some absolute verdict (like one of guilty/not guilty on a man) on what is described in the "ought" sentences used in certain types of context: not merely the contexts that Aristotle would call "moral" — passions and actions — but also some of the contexts that he would call "intellectual." 

The ordinary (and quite indispensable) terms "should," "needs," "ought," "must" — acquired this special sense by being equated in the relevant contexts with "is obliged," or "is bound," or "is required to," in the sense in which one can be obliged or bound by law, or something can be required by law.

How did this come about? The answer is in history: between Aristotle and us came Christianity, with its law conception of ethics. For Christianity derived its ethical no- tions from the Torah. [...]

In consequence of the dominance of Christianity for many centuries, the concepts of being bound, permitted, or excused became deeply embedded in our language and thought. The Greek word "aiu,avravav," the aptest to be turned to that use, acquired the sense "sin," from having meant "mistake," "missing the mark," "going wrong." The Latin peccatum which roughly corresponded to aiu,avriiu,a was even apter for the sense "sin," because it was already associated with "culpa" — "guilt" — a juridical notion. The blanket term "illicit," "unlawful," meaning much the same as our blanket term "wrong," explains itself. It is interesting that Aristotle did not have such a blanket term. He has blanket terms for wickedness — "villain," "scoundrel"; but of course a man is not a villain or a scoundrel by the performance of one bad action, or a few bad actions. And he has terms like "disgraceful," "impious"; and specific terms signifying defect of the relevant virtue, like "unjust"; but no term corresponding to "illicit." The extension of this term (i.e. the range of its application) could be indicated in his terminology only by a quite lengthy sentence: that is "illicit" which, whether it is a thought or a consented-to passion or an action or an omission in thought or action, is something contrary to one of the virtues the lack of which shows a man to be bad qua man. That formulation would yield a concept co-extensive with the concept "illicit." 

To have a law conception of ethics is to hold that what is needed for conformity with the virtues failure in which is the mark of being bad qua man (and not merely, say, qua craftsman or logician) — that what is needed for this , is required by divine law. Naturally it is not possible to have such a conception unless you believe in God as a law-giver; like Jews, Stoics, and Christians. But if such a conception is dominant for many centuries, and then is given up, it is a natural result that the concepts of "obligation," of being bound or required as by a law, should remain though they had lost their root; and if the word "ought" has become invested in certain contexts with the sense of "obligation," it too will remain to be spoken with a special emphasis and special feeling in these contexts.

It is as if the notion "criminal" were to remain when criminal law and criminal courts had been abolished and forgotten. A Hume discovering this situation might conclude that there was a special sentiment, expressed by "criminal," which alone gave the word its sense. So Hume discovered the situation which the notion "obligation" survived, and the notion "ought" was invested with that peculiar for having which it is said to be used in a "moral" sense, but in which the belief in divine law had long since been abandoned: for it was substantially given up among Protestants at the time of the Reformation.2The situation, if I am right, was the interesting one of the survival of a concept outside the framework of thought that made it a really intelligible one.