A philosopher who has no connection to geometry is only half a philosopher, and a mathematician who has no philosophical vein is only half a mathematician.

Thus, I blush to add, you can not be a philosopher and a good man, though you may be a philosopher and a great one.

...all of the philosophers put together are not worth a single saint.

I think so badly of philosophy that I don't like to talk about it. ... I do not want to say anything bad about my dear colleagues, but the profession of teacher of philosophy is a ridiculous one. We don't need a thousand of trained, and badly trained, philosophers — it is very silly. Actually most of them have nothing to say.

And as any mixed-race person will tell you — to be half of two things is to be whole of nothing.

A man without persistence will never make a good shaman or a good physician.

The division of Philosopher and Poet is only apparent, and to the disadvantage of both. It is a sign of disease, and of a sickly constitution.

Four thousand volumes of metaphysics will not teach us what the soul is.

Ein Philosoph, der keine Beziehung zur Geometrie hat, ist nur ein halber Philosoph, und ein Mathematiker, der keine philosophische Ader hat, ist nur ein halber Mathematiker.

To be half of one can only be a torment when the other half is gone.

... a hundred fools together will not make one wise man.

In practice people who study philosophy too long become very odd birds, not to say thoroughly vicious; while even those who are the best of them are reduced by...[philosophy] to complete uselessness as members of society.

No philosopher allows his opinions to be swayed by facts—he would be kicked out of his guild. Theologians, the lot of them.

You can't be a philosopher and an activist. If you do, you get all mixed up.