Only the fittest will survive.

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

I am dying by inches, from not having anybody to talk to about insects.

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

An agnostic would be the more correct description of my state of mind.

Much love many trials, but what an utter desert is a life without love.

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

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

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

Intelligence is based on how efficient a species became at doing the things they need to survive.

It is impossible to conceive of this immense and wonderful universe as the result of blind chance or necessity.

I am not apt to follow blindly the lead of other men

Some call it evolution, And others call it God.

It is always advisable to perceive our ignorance.

Man, wonderful man, must collapse, into nature's cauldron, he is no deity, he is no exception.

A mathematician is a blind man in a dark room looking for a black cat that isn't there.

Ignorance more frequently begets confidence than does knowledge.

The more one thinks the more one feels the hopeless immensity of man's ignorance.

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