It is always advisable to perceive clearly our ignorance.

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.

In my most extreme fluctuations I have never been an atheist in the sense of denying the existence of a God ... I think that generally (& more and more so as I grow older) but not always, that an agnostic would be the most correct description of my state of mind.

It is like confessing to a murder.

A grain in the balance will determine which individual shall live and which shall die - which variety or species shall increase in number, and which shall decrease, or finally become extinct.

If every one were cast in the same mould, there would be no such thing as beauty.

It's not the strongest, but the most adaptable that survive.