It is not necessary to fathom the ground or the structure of everything in order to know what to make of it. Stones do not disconcert a builder because he may not happen to know what they are chemically; and so the unsolved problems of life and nature, and the Babel of society, need not disturb the genial observer, though he may be incapable of unravelling them.
He may set these dark spots down in their places, like so many caves or wells in a landscape, without feeling bound to scrutinise their depths simply because their depths are obscure. Unexplored they may have a sort of lustre, explored they might merely make him blind, and it may be a sufficient understanding of them to know that they are not worth investigating. In this way the most chaotic age and the most motley horrors might be mirrored limpidly in a great mind, as the Renaissance was mirrored in the works of Raphael and Shakespeare; but the master's eye itself must be single, his style unmistakable, his visionary interest in what he depicts frank and supreme.
Hence this comprehensive sort of greatness too is impossible in an age when moral confusion is pervasive, when characters are complex, undecided, troubled by the mere existence of what is not congenial to them, eager to be not themselves; when, in a word, thought is weak and the flux of things overwhelms it.
George Santayana - Winds Of Doctrine: Studies in Contemporary Opinion (1913)