No problem can be solved from the same level of consciousness that created it.

The measure of intelligence is the ability to change.

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.

One must take what nature gives as one finds it.

The goal of pacifism is possible only though a supranational organization. To stand unconditionally for this cause is the criterion of true pacifism.

God does not care about our mathematical difficulties. He integrates empirically.

I must be willing to give up what I am in order to become what I will be.