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.

Relativity applies to physics, not ethics

Relativity applies to physics, not ethics

In scientific work, those who refuse to go beyond fact rarely get as far as fact.

In scientific work, those who refuse to go beyond fact rarely get as far as fact.

How empty is theory in the presence of fact

How empty is theory in the presence of fact

Many things difficult to design prove easy to performance.

Many things difficult to design prove easy to performance.

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

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

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.