“With most animals, as with man, the alertness of the senses diminishes after years of work, after domestic habits and progress of culture.”

“This view of a living nature where man is nothing is both odd and sad. Here, in a fertile land, in an eternal greenness, you search in vain for traces of man; you feel you are carried into a different world from the one you were born into.”

“Die gefährlichste Weltanschauung ist die Weltanschauung derer, die die Welt nie angeschaut haben. (The most dangerous worldview is the worldview of those who have not viewed the world)”

“There are three stages of scientific discovery: first people deny it is true; then they deny it is important; finally they credit the wrong person.”

“I am more and more convinced that our happiness or unhappiness depends more on the way we meet the events of life than on the nature of those events themselves.”

“The best and noblest parts of man depend precious little on culture, education, and whatever else it is called. One can never have enough respect for true humanity as it is visible in the persons of the totally uneducated classes, and never enough humility if one sometimes believes one is superior to them.”

“Joy mingled with sadness, even with grief, is the deepest human joy. It winds itself about the soul with indescribable sweetness, with a dim but unerring sense for what will some day be born of it.”