Every serious scientific worker is painfully conscious of this involuntary relegation to an ever-narrowing sphere of knowledge, which threatens to deprive the investigator of his broad horizon and degrades him to the level of a mechanic.

Each act is an island in time, to be judged on its own.

It has often been said, and certainly not without justification, that the man of science is a poor philosopher.

Man, surrounded by facts, permitting himself no surprise, no intuitive flash, no great hypothesis, no risk, is in a locked cell. Ignorance cannot seal the mind and imagination more securely.

Nationalism is an infantile disease. It is the measles of mankind.

Einstein was attending a music salon in Germany before the second world war, with the violinist S. Suzuki. Two Japanese women played a German piece of music and a woman in the audience exclaimed: "How wonderful! It sounds so German!" Einstein responded: "Madam, people are all the same."

It is the theory that decides what can be observed.