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

I am turned into a sort of machine for observing facts and grinding out conclusions.

It is a cursed evil to any man to become as absorbed in any subject as I am in mine.

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

The very essence of instinct is that it’s followed independently of reason.

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

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.

I have tried lately to read Shakespeare, and found it so intolerably dull that it nauseated me.

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.

The highest possible stage in moral culture is when we recognize that we ought to control our thoughts.

Man tends to increase at a greater rate than his means of subsistence.

A moral being is one who is capable of reflecting on his past actions and their motives – of approving of some and disapproving of others.

To kill an error is as good a service as, and sometimes even better than, the establishing of a new truth or fact.

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.

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

Man is descended from a hairy, tailed quadruped, probably arboreal in its habits.

False facts are highly injurious to the progress of science, for they often endure long; but false views, if supported by some evidence, do little harm, for every one takes a salutary pleasure in proving their falseness.

How paramount the future is to the present when one is surrounded by children.

At some future period, not very distant as measured by centuries, the civilized races of man will almost certainly exterminate, and replace the savage races throughout the world.

I love fools’ experiments. I am always making them.

I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection.

In the long history of humankind (and animal kind, too) those who learned to collaborate and improvise most effectively have prevailed.

A man’s friendships are one of the best measures of his worth.

Animals, whom we have made our slaves, we do not like to consider our equal.

An American monkey, after getting drunk on brandy, would never touch it again, and thus is much wiser than most men.

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.

It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.

What a book a devil’s chaplain might write on the clumsy, wasteful, blundering, low, and horribly cruel work of nature!

The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain an agnostic.

On the ordinary view of each species having been independently created, we gain no scientific explanation.

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