Nature reacts not only to physical disease, but also to moral weakness; when the danger increases; she gives us greater courage

The decline of literature indicates the decline of a nation.

I could never have known so well how paltry men are, and how little they care for really high aims, if I had not tested them by my scientific researches. Thus I saw that most men only care for science so far as they get a living by it, and that they worship even error when it affords them a subsistence.

We are pantheists when we study nature, polytheists when we write poetry, monotheists in our morality.

Gray are all the theories, But green is the tree of life.

Truth has to be repeated constantly, because Error also is being preached all the time, and not just by a few, but by the multitude. In the Press and Encyclopaedias, in Schools and Universities, everywhere Error holds sway, feeling happy and comfortable in the knowledge of having Majority on its side.

There is nothing in the world more shameful than establishing one's self on lies and fables.