If a man has any greatness in him, it comes to light, not in one flamboyant hour, but in the ledger of his daily work.

We fly, but we have not 'conquered' the air. Nature presides in all her dignity, permitting us the study and the use of such of her forces as we may understand. It is when we presume to intimacy, having been granted only tolerance, that the harsh stick fall across our impudent knuckles and we rub the pain, staring upward, startled by our ignorance.

all the science of flying has been captured in the breadth of an instrument board, but not the religion of it.

Memory is a drug. Memory can hold you against your strength and against your will.

To see ten thousand animals untamed and not branded with the symbols of human commerce is like scaling an unconquered mountain for the first time, or like finding a forest without roads or footpaths, or the blemish of an axe. You know then what you had always been told -- that the world once lived and grew without adding machines and newsprint and brick-walled streets and the tyranny of clocks.

I suppose if there were a part of the world in which mastodon still lived, somebody would design a new gun, and men, in their eternal impudence, would hunt mastodon as they now hunt elephant. Impudence seems to be the word. At least David and Goliath were of the same species, but, to an elephant, a man can only be a midge with a deathly sting.

A man can be riddled with malaria for years on end, with its chills and its fevers and its nightmares, but if one day he sees that the water from his kidneys is black, he knows he will not leave that place again, wherever he is, or wherever he hoped to be.