Body and soul are not two different things, but only two different ways of perceiving the same thing. Similarly, physics and psychology are only different attempts to link our experiences together by way of systematic thought.

My interest in science was always essentially limited to the study of principles.... That I have published so little is due to this same circumstance, as the great need to grasp principles has caused me to spend most of my time on fruitless pursuits.

Just because you believe in something does not mean that it is true.

It should be possible to explain the laws of physics to a barmaid.

The only rational way of educating is to be an example. If one can't help it, a warning example.

About God, I cannot accept any concept based on the authority of the Church... As long as I can remember. I have resented mass indoctrination. I cannot prove to you there is no personal God, but if I were to speak of him, I would be a liar. I do not believe in the God of theology who rewards good and punishes evil. His universe is not ruled by wishful thinking, but by immutable laws

It is true that the grasping of truth is not possible without empirical basis. However, the deeper we penetrate and the more extensive and embracing our theories become the less empirical knowledge is needed to determine those theories.