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 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.

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

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

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.

How empty is theory in the presence of fact

How empty is theory in the presence of fact

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

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

An ounce of action is worth a ton of theory.

An ounce of action is worth a ton of theory.

It is the theory that decides what can be observed

It is the theory that decides what can be observed