His superiority over other learned men consisted chiefly in what may be called the art of thinking, the art of using his mind; a certain continual power of seizing the useful substance of all that he knew, and exhibiting it in a clear and forcible manner; so that knowledge, which we often see to be no better than lumber in men of dull understanding, was, in him, true, evident, and actual wisdom.

James Boswell, on Johnson, in his Life of Samuel Johnson