Knowledge does not come to us by details, but in flashes of light from heaven.
 Henry David Thoreau, Life Without Principle (1863). copy citation

Context

“Conventionalities are at length as bad as impurities. Even the facts of science may dust the mind by their dryness, unless they are in a sense effaced each morning, or rather rendered fertile by the dews of fresh and living truth. Knowledge does not come to us by details, but in flashes of light from heaven. Yes, every thought that passes through the mind helps to wear and tear it, and to deepen the ruts, which, as in the streets of Pompeii, evince how much it has been used. How many things there are concerning which we might well deliberate, whether we had better know them,—had better let their peddling-carts be driven, even at the slowest trot or walk, over that bridge of glorious span by which we trust to ​pass at last from the farthest brink of time to the nearest shore of eternity!” source