Many must have quoted the stately tag from Virgil which says, “Happy were he who could know the causes of things,” without remembering in what context it comes. Many have probably quoted it because the others have quoted it. Many, if left in ignorance to guess whence it comes, would probably guess wrong. Everybody knows that Virgil, like Homer, ventured to describe boldly enough the most secret councils of the gods. Everybody knows that Virgil, like Dante, took his hero into Tartarus and the labyrinth of the last and lowest foundations of the universe. Every one knows that he dealt with the fall of Troy and the rise of Rome, with the laws of an empire fitted to rule all the children of men, with the ideals that should stand like stars before men committed to that awful stewardship. Yet it is in none of these connections, in none of these passages, that he makes the curious remark about human happiness consisting in a knowledge of causes. He says it, I fancy, in a pleasantly didactic poem about the rules for keeping bees. Anyhow, it is part of a series of elegant essays on country pursuits, in one sense, indeed, trivial, but in another sense almost technical. It is in the midst of these quiet and yet busy things that the great poet suddenly breaks out into the great passage, about the happy man whom neither kings nor mobs can cow; who, having beheld the root and reason of all things, can even hear under his feet, unshaken, the roar of the river of hell.
— The Outline of Sanity (1926).