One reason why mathematics enjoys special esteem, above all other sciences, is that its laws are absolutely certain and indisputable, while those of other sciences are to some extent debatable and in constant danger of being overthrown by newly discovered facts.

How can it be that mathematics, being, after all, a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality? Is human reason, then, without experience, merely by taking thought, able to fathom the properties of real things?

Science is international but its success is based on institutions, which are owned by nations. If therefore, we wish to promote culture we have to combine and to organize institutions with our own power and means.

I should unconditionally refuse every direct or indirect war service and try to induce my friends to adopt the same attitude, irrespective of the general opinion of the causes of war.

If A is success in life, then A = x + y + z. Work is x, play is y and z is keeping your mouth shut.

Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in point of fact, religious.

Whether you can observe a thing or not depends on the theory which you use. It is the theory which decides what can be observed.

May they not forget to keep pure the great heritage that puts them ahead of the West: the artistic configuration of life, the simplicity and modesty of personal needs, and the purity and serenity of the Japanese soul.

I have come to believe that the motion of the Earth cannot be detected by any optical experiment.

I was sitting in a chair in the patent office at Bern when all of sudden a thought occurred to me: If a person falls freely he will not feel his own weight. I was startled. This simple thought made a deep impression on me. It impelled me toward a theory of gravitation.