Considered logically this concept is not identical with the totality of sense impressions referred to; but it is an arbitrary creation of the human (or animal) mind.

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

You believe in a God who plays dice, I in complete law and order.

All that is valuable in human society depends upon the opportunity for development accorded the individual.

This is a question too difficult for a mathematician. It should be asked of a philosopher"(when asked about completing his income tax form)

But if the longing for the achievement of the goal is powerfully alive within us, then shall we not lack the strength to find the means for reaching the goal and for translating it into deeds.

I always have a high regard for the individual and have an insuperable distaste for violence and clubmanship. All these motives made me into a passionate pacifist and anti-militarist. I am against any nationalism, even in the guise of mere patriotism. Privileges based on position and property have always seemed to me unjust and pernicious, as did any exaggerated personality cult.