[Freud's] sense of reality is less clouded by wishful thinking than is the case with other people and [he combines] the qualities of critical judgment, earnestness and responsibility.

There will come a point in everyone's life , however, where only intuition can make the leap ahead, without ever knowing precisely how. One can never know why but one must accept intuition as a fact.

A little knowledge is a dangerous thing. So is a lot.

It's very depressing to live in a time where it's easier to break an atom than a prejudice.

Everyone must become their own person, however frightful that may be.

It is my conviction that pure mathematical construction enables us to discover the concepts and the laws connecting them, which gives us the key to the understanding of nature ... In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.

Only in mathematics and physics was I, through self-study, far beyond the school curriculum, and also with regard to philosophy as it was taught in the school curriculum.