Politics is far more complicated than physics.

The only real valuable thing is intuition. The intellect has little to do on the road to discovery

Humankind's desire for peace can be realized only by the creation of a world government.

It is my inner conviction that the development of science seeks in the main to satisfy the longing for pure knowledge.

A scientist is a mimosa when he himself has made a mistake, and a roaring lion when he discovers a mistake of others.

At the same time, as social beings, we are moved in the relations with our fellow beings by such feelings as sympathy, pride, hate, need for power, pity, and so on.

My pacifism is an instinctive feeling, a feeling that possesses me because the murder of men is disgusting. My attitude is not derived from any intellectual theory but is based on my deepest antipathy to every kind of cruelty and hatred.