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.

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.

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.

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

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

Conjecture as to things useful, is good; but conjecture as to what it would be useless to know, is very read more

Conjecture as to things useful, is good; but conjecture as to what it would be useless to know, is very idle.

An ounce of action is worth a ton of theory.

An ounce of action is worth a ton of theory.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

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

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