Superficial knowledge ... is hurtful to those who possess true genius; for it necessarily draws them away from their main object, wastes their industry over details and subjects foreign to their needs and natural talent, and lastly does not serve, as they flatter themselves, to prove the breadth of their mind. In all ages there have been men of very moderate intelligence who knew much, and so on the contrary, men of the highest intelligence who knew very little. Ignorance is not lack of intelligence, nor knowledge a proof of genius.