"Power Tends To Corrupt, And Absolute Power Corrupts Absolutely."
I hope I will not be drummed out of the corps of Social Science if I confess to the fact that I can't think of an explanation in our field that is both elegant and beautiful. Perhaps deep . . . I guess we are still too young to have explanations of that sort . . . But there is one elegant and deep statement (which, alas, is not quite an "explanation") that comes close to fulfilling the criteria, and that I find very useful as well as beautifully simple.
I refer to the well-known lines Lord Acton wrote in a letter from Naples in 1887 to the effect that: "Power tends to corrupt, and absolute power corrupts absolutely." At least one philosopher of science has written that on this sentence an entire science of human beings could be built.
I find that the sentence offers the basis for explaining how a failed painter like Adolph Hitler and a failed seminarian like Joseph Stalin could end up with the blood of millions on their hands; or how the Chinese emperors, the Roman popes, or the French aristocracy failed to resist the allure of power. When a religion or ideology becomes dominant, the lack of controls will result in widening spirals of license leading to degradation and corruption.
It would be nice if Acton's insight could be developed into a full-fledged explanation before the hegemonies of our time, based on blind faith in science and the worship of the Invisible Hand, follow former forms of power in the dustbins of history.