Joseph Epstein in Commentary Magazine:
I have met six Nobel Prize winners, and none has come close, in my view, to qualifying as a genius. Three won the prize for economics. They were all supremely confident and no doubt highly intelligent, but, I thought, insufficiently impressed by the mysteries of life. Another won his for physics, but in my company he wished to talk only about Shakespeare, on which he was commonplace and extremely boring. Another was a laureate for biology; he seemed to me, outside the laboratory, a man without the least subtlety. The last won his Nobel Prize for literature, and the most profound thing about him was the extent to which he had screwed up his personal life. Somehow it is always sensible to remember that in 1949 the Nobel Prize in medicine was given to Antonio Egas Moniz, a Portuguese surgeon, for developing the procedure known as the lobotomy.
Genius is rare. Schopenhauer thought a genius was one in a hundred million. In this realm if in no other, that most pessimistic of philosophers may have been optimistic. Distinguishing between a man of learning and a genius, Schopenhauer wrote: “A man of learning is a man who has learned a great deal; a man of genius, one from whom we learn something which the genius has learned from nobody.” A genius is not merely brilliant, skillful, masterly, sometimes dazzling; he is miraculous, in the sense that his presence cannot be predicted, explained, or accounted for (at least thus far) by natural laws or scientific study. The definitions for genius may be greater than the actual number of true geniuses who have walked the earth. My own definition is as follows: Be he a genius of thought, art, science, or politics, a genius changes the way the rest of us hear or see or think about the world.
More here.