The Two Sources of Morality and Religion (1932) is a book that I have taken up in the past which failed to adhere then but somehow is doing so now. With work of this order of difficulty there has to be a feeling that it is speaking to us. He introduces the concept of two levels of moral engagement, the basic level of group behavioural constraints which are obligatory and virtually instinctual and advancing on from there to the involvement with an exemplar that embodies values that are satisfying and give us joy.
Who can help seeing that social cohesion is largely due to the necessity for a community to protect itself against others, and that it is primarily as against all other men that we love the men with whom we live? Such is the primitive instinct. It is still there, though fortunately hidden under the accretions of civilization; but even to-day we still love naturally and directly our parents and our fellow-countrymen, whereas love of mankind is indirect and acquired. We go straight to the former, to the latter we only come by roundabout ways; for it is only through God, in God, that religion bids man love mankind; and likewise it is through reason alone, that Reason in whose communion we are all partakers, that philosophers make us look at humanity in order to show us the pre-eminent dignity of the human being, the right of all to command respect. Neither in the one case nor the other do we come to humanity by degrees, through the stages of the family and the nation. We must, in a single bound, be carried far beyond it, and, without having made it our goal, reach it by outstripping it. Besides, whether we speak the language of religion or the language of philosophy, whether it be a question of love or respect, a different morality, another kind of obligation supervenes, above and beyond the social pressure.
He himself had moved towards Catholicism as the fulfillment, as he expressed it, of Judaism yet he was not baptized sensing the rise of antisemitism and thereby giving a witness to primal instinctual tribal loyalty. His queuing in bad weather to be registered as a Jew in 1941 was the direct cause of his death.