Dennis Prager , in this episode of his Prager University series of videos, takes on an ever popular heresy: evil is irrational. This heresy is popular for any number of reasons but doubtless it all boils down to the belief, completely unfounded in human experience, that reasonable people will agree on what is good and what is evil. The experience of the last half century in the West should have knocked that bit of foolishness into a cocked hat. Agreement on good and evil in practice is largely a matter of convention. If the social norms of a people come under challenge, we quickly see apparently reasonable people disagreeing on such fundamental questions as whether an unborn child has a right to life, or whether sex outside of marriage is evil.
Concepts of good and evil are either based on revelation from God, or are matters of opinion to be argued about. Fewer people in our society believe in revelation, hence good and evil become matters of opinion for debate. When the debate is joined we often find that there is little agreement on goals and that therefore what is rational to each individual takes varying paths to differing goals. Widespread disagreement on good and evil also causes the State to grow ever larger to enforce the version of good held by those in power in the State. John Adams saw all this when he wrote on October 11, 1798 a letter to the officers of the first brigade of the third division of the Massachusetts militia:
While our country remains untainted with the principles and manners which are now producing desolation in so many parts of the world; while she continues sincere, and incapable of insidious and impious policy, we shall have the strongest reason to rejoice in the local destination assigned us by Providence. But should the people of America once become capable of that deep simulation towards one another, and towards foreign nations, which assumes the language of justice and moderation, while it is practising iniquity and extravagance, and displays in the most captivating manner the charming pictures of candour, frankness, and sincerity, while it is rioting in rapine and insolence, this country will be the most miserable habitation in the world. Because we have no government, armed with power, capable of contending with human passions, unbridled by morality and religion. Avarice, ambition, revenge and licentiousness would break the strongest cords of our Constitution, as a whale goes through a net. Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other. Oaths in this country are as yet universally considered as sacred obligations. That which you have taken, and so solemnly repeated on that venerable ground, is an ample pledge of your sincerity and devotion to your country and its government.