"Nevertheless so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being... as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life!"
"The loss of these tastes [for poetry and music] is a loss of happiness, and may possibly be injurious to the intellect, and more probably to the moral character, by enfeebling the emotional part of our nature."
"For my own part I would as soon be descended from that heroic little monkey... or from that old baboon, who... carried away in triumph his young comrade... as from a savage who delights to torture his enemies... and is haunted by the grossest superstitions."
"But then with me the horrid doubt always arises whether the convictions of man's mind... are of any value or at all trustworthy. Would any one trust in the convictions of a monkey's mind?"
"Man in his arrogance thinks himself a great work, worthy of the interposition of a deity. More humble, and I believe truer, to consider him created from animals."
"Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult--at least I have found it so--than constantly to bear this conclusion in mind."