Animals manifestly enjoy excitement, and suffer from annul and may exhibit curiosity.

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

Our faculties are more fitted to recognize the wonderful structure of a beetle than a Universe.

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

The voyage of the Beagle has been by far the most important event in my life and has determined my whole career; yet it depended on so small a circumstance as my uncle offering to drive me 30 miles to Shrewsbury, which few uncles would have done, and on such a trifle as the shape of my nose.

As natural selection acts by competition, it adapts the inhabitants of each country only in relation to the degree of perfection of their associates; so that we need feel no surprise at the inhabitants of any one country, although on the ordinary view supposed to have been specially created and adapted for that country, being beaten and supplanted by the naturalised productions from another land.

I have deeply regretted that I did not proceed far enough at least to understand something of the great leading principles of mathematics, for men thus endowed seem to have an extra sense.