Whenever a theory appears to you as the only possible one, take this as a sign that you have neither read more

Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve

Relativity applies to physics, not ethics

Relativity applies to physics, not ethics

You cannot run a business, or anything else, on a theory.

You cannot run a business, or anything else, on a theory.

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in read more

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in connection with the electric light ... Yet in only two cases did my experiments prove the truth of my theory.

A young boy is a theory, an old man is a fact.

A young boy is a theory, an old man is a fact.

In theory there is no difference between theory and practice. In practice there is.

In theory there is no difference between theory and practice. In practice there is.

It is the theory that decides what can be observed

It is the theory that decides what can be observed

How empty is theory in the presence of fact

How empty is theory in the presence of fact

A theory has only the alternative of being right or wrong. A model has a third possibility - it may read more

A theory has only the alternative of being right or wrong. A model has a third possibility - it may be right but irrelevant.