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.

Let us work without theorizing, 'Tis the only way to make life endurable.

Let us work without theorizing, 'Tis the only way to make life endurable.

Relativity applies to physics, not ethics

Relativity applies to physics, not ethics

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

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

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.

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

Many things difficult to design prove easy to performance.

Many things difficult to design prove easy to performance.

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.

A theory is no more like a fact than a photograph is like a person.

A theory is no more like a fact than a photograph is like a person.