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.

He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never read more

He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast.

It is the theory that decides what can be observed

It is the theory that decides what can be observed

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.

There can be no theory of any account unless it corroborate with the theory of the earth.

There can be no theory of any account unless it corroborate with the theory of the earth.

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.

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.

How empty is theory in the presence of fact

How empty is theory in the presence of fact