The more I learn of physics, the more I am drawn to metaphysics.

The most important human endeavor is the striving for morality in our actions. Our inner balance and even our very existence depend on it. Only morality in our actions can give beauty and dignity to life. To make this a living force and bring it to clear consciousness is perhaps the foremost task of education. The foundation of morality should not be made dependent on myth nor tied to any authority lest doubt about the myth or about the legitimacy of the authority imperil the foundation of sound judgment and action.

Nothing truly valuable can be achieved except by the unselfish cooperation of many individuals.

There is only one road to human greatness: through the school of hard knocks.

The beauty of it is that we have to content ourselves with the recognition of the miracle, beyond which there is no legitimate way out.

All these constructions and the laws connecting them can be arrived at by the principle of looking for the mathematically simplest concepts and the link between them.

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.