It is scarcely possible to doubt that the love of man has become instinctive in the dog.

Farewell Australia! You ... are too great and ambitious for affection, yet not great enough for respect. I leave your shores without sorrow or regret.

It may be said that natural selection is daily and hourly scrutinizing, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, wherever and whenever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.

Freedom of thought is best promoted by the gradual illumination of men’s minds which follows from the advance of science.

There is no fundamental difference between man and animals in their ability to feel pleasure and pain, happiness, and misery.

On your life, underestimating the proclivities of finches is likely to lead to great internal hemorrhaging.

I am actually weary of telling people that I do not pretend to adduce [direct] evidence of one species changing into another, but I believe that this view is in the main correct, because so many phenomena can thus be grouped end explained.