The Fear of Being Found Out
... We know that conscience enjoins different acts in different parts of the world, and that broadly speaking it is everywhere in agreement with tribal custom. What, then, is really happening when a man's conscience pricks him?
The word 'conscience' covers, as a matter of fact, several different feelings; the simplest of these is the fear of being found out. Yor, reader, have, I am sure, lived a completely blameless life, but if you will ask someone who has at some time acted in a manner for which he would be punished if it became known, you will find that, when discovery seemed imminent, the person in question repented of his crime. I do not say that this would apply to the professional thief who expects a certain amount of prison as a trade risk, but it applies to what may be called the respectable offender, such as the Bank Manager who has embezzled in a moment of stress, or the clergyman who has been tempted by passion into some sensual irregularity. Such men can forget their crime when there seems little chance of detection, but when they are found out, or in grave danger of being so, they wish they had been more virtuous, and this wish may give them a lively sense of the enormity of the sin. Closely allied with this feeling is the fear of becoming an outcast from the herd.
(From: The Conquest of Happiness, 1930, chap. 7. )