I find it difficult to believe that I belong to such an idiotic, rotten species - the species that actually boasts of its freedom of will, heroism on command, senseless violence, and all of the loathsome nonsense that goes by the name of patriotism.

A hundred times every day I remind myself that my inner and outer life are based on the labors of others.

The longing to behold this pre-established harmony [of phenomena and theoretical principles] is the source of the inexhaustible patience and perseverance with which Planck has devoted himself ... The state of mind which enables a man to do work of this kind is akin to that of the religious worshiper or the lover; the daily effort comes from no deliberate intention or program, but straight from the heart.

The scientist finds his reward in what Henri Poincare calls the joy of comprehension, and not in the possibility of application to which any discovery may lead.

The basic laws of the universe are simple, but because our senses are limited, we can’t grasp them. There is a pattern in creation.

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.

The only way to escape the corruptible effect of praise is to go on working.