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.

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.

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

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

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

[Do not] put too much confidence in experimental results until they have been confirmed by theory.

[Do not] put too much confidence in experimental results until they have been confirmed by theory.

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

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

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

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

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

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

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.