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.

There can be no theory of any account unless it corroborate with the theory of the earth.

There can be no theory of any account unless it corroborate with the theory of the earth.

Many things difficult to design prove easy to performance.

Many things difficult to design prove easy to performance.

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.

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

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

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.

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.

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.

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in read more

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in connection with the electric light ... Yet in only two cases did my experiments prove the truth of my theory.