To a Frenchman like M. Renan, intelligence does not mean a quickness of wit, a ready dexterity in handling ideas, or even a ready accessibility to ideas. It implies those, of course, but it does not mean them; and one should perhaps say in passing that it does not mean the pert and ignorant cleverness that current vulgar usage has associated with the word. Again it is our common day-to-day experience that gives us the best possible assistance in establishing the necessary differentiations. We have all seen men who were quick witted, accessible to ideas and handy with their management of them, whom we should yet hesitate to call intelligent; we are conscious that the term does not quite fit. The word sends us back to a phrase of Plato. The person of intelligence is the one who always tends to “see things as they are,” the one who never permits his view of them to be directed by convention, by the hope of advantage, or by an irrational and arbitrary authoritarianism. He allows the current of his consciousness to flow in perfect freedom over any object that may be presented to it, uncontrolled by prejudice, prepossession or formula; and thus we may say that there are certain integrities at the root of intelligence which give it somewhat the aspect of a moral as well as an intellectual attribute.
Albert Jay Nock, The Theory of Education in the United States