In the survival of favoured individuals and races, during the constantly-recurring struggle for existence, we see a powerful and ever-acting form of selection.

We must, however, acknowledge, as it seems to me, that man with all his noble qualities... still bears in his bodily frame the indelible stamp of his lowly origin.

My mind seems to have become a kind of machine for grinding general laws out of large collections of facts.

A scientific man ought to have no wishes, no affections, - a mere heart of stone.

We can allow satellites, planets, suns, universe, nay whole systems of universes, to be governed by laws, but the smallest insect, we wish to be created at once by special act.

Ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science.

I cannot persuade myself that a beneficent and omnipotent God would have designedly created parasitic wasps with the express intention of their feeding within the living bodies of Caterpillars.

If the misery of the poor be caused not by the laws of nature, but by our institutions, great is our sin.

A man who dares to waste one hour of time has not discovered the value of life.