Everybody acts not only under external compulsion but also in accordance with inner necessity.

The really valuable method of thought to arrive at a logically coherent system is intuition.

What humanity owes to personalities like Buddha, Moses, and Jesus ranks for me higher than all the achievements of the enquiring and constructive mind.

Science is a wonderful thing if one does not have to earn one's living at it.

Nobody knows how the stand of our knowledge about the atom would be without him. Personally, [Niels] Bohr is one of the amiable colleagues I have met. He utters his opinions like one perpetually groping and never like one who believes himself to be in possession of the truth.

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.

Mozart's music is so pure and beautiful that I see it as a reflection of the inner beauty of the universe.