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.

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.

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.

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.

An ounce of action is worth a ton of theory.

An ounce of action is worth a ton of theory.

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.

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.

There is a theory which states that if ever for any reason anyone discovers what exactly the Universe is for read more

There is a theory which states that if ever for any reason anyone discovers what exactly the Universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened.