There is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance.

On the other hand, the concept owes its meaning and its justification exclusively to the totality of the sense impressions which we associate with it.

Since I have introduced this term I had always a bad conscience. . . . I cannot help to feel it strongly and I am unable to believe that such an ugly thing should be realized in nature.

There does, in fact, appear to be a plan.

The number of natural hypothesis that can explain any given phenomena is infinite.

The distinctions separating the social classes are false; in the last analysis they rest on force.

The world we have created is a product of our thinking.