Anscombe says that we only think in terms of moral laws and obligations because Christianity was dominant in our culture for so long.
It is as if the notion “criminal” were to remain whenAnscombe thinks that we also need to distinguish again between the intended (you are responsible for whether you do the unethical deed or not) and the merely foreseen (you are not responsible for this foreseen event that you do not intend).
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. The 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.
G E M Anscombe on Moral Philosophy