In the American Jungle by Waldo David Frank

Most men are set and long past growing before they are forty. This is true of the conspicuous and successful, no less than of the common. They have contrived, from their first impacts with the world, some attitude, trick or gesture; it works; they stick to it until they are repetitive as machines. Herbert Croly was a growing man until he was stricken; and the rate of his growth kept on accelerating with the years. This rare capacity, which toward the end transfigured him, was his true genius.

If we analyze the nature of his growth, we come close to the man, and understand what made him so sound and beautiful a being. And the first trait upon which we come is his humility. Herbert Croly was authentically humble. Not humble with the inverted pride of a Franciscan or of a character of Dostoevski's-because of raging lusts intolerable to himself which he had to flay into their opposite lest they drive him mad. Herbert Croly's humility came from a true sense of himself in the world-a sense of true proportion. In the years when I knew him, at least, he never seemed to be looking upon himself alone: always, he felt and saw and thought himself within a texture that was the world. From this proportion came sobriety and humility; and from this organic contact with life's sources, a springlike energy that kept him growing.