" However much the theory of political realism may have been misunderstood and misinterpreted, there is no gainsaying its distinctive intellectual and moral attitude to matters political.
Intellectually, the political realist maintains the autonomy of the political sphere, as the economist, the lawyer, the moralist maintain theirs. He thinks in terms of interest defined as power, as the economist thinks in terms of interest defined as wealth; the lawyer, of the conformity of action with legal rules; the moralist, of the conformity of action with moral principles. The economist asks: "How does this policy affect the wealth of society, or a segment of it?" The lawyer asks: "Is this policy in accord with the rules of law?" The moralist asks: "Is this policy in accord with moral principles?" And the political realist asks: "How does this policy affect the power of the nation? "

― Hans J. Morgenthau , Politics Among Nations