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.

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.

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

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

There is a theory which states that if ever for any reason anyone discovers what exactly the Universe is for read more

There is a theory which states that if ever for any reason anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.

Our theories of the eternal are as valuable as are those which a chick which has not broken its way read more

Our theories of the eternal are as valuable as are those which a chick which has not broken its way through its shell might form of the outside world.

If the facts don't fit the theory, change the facts.

If the facts don't fit the theory, change the facts.

You have to know you can first. How comes later.

You have to know you can first. How comes later.

An ounce of action is worth a ton of theory.

An ounce of action is worth a ton of theory.

It is the theory that decides what can be observed

It is the theory that decides what can be observed