The scientific theory I like best is that the rings of Saturn are composed entirely of lost airline luggage.
We must respect the other fellow's religion, but only in the sense and to the extent that we respect his theory that his wife is beautiful and his children smart.
Science is organized common sense where many a beautiful theory was killed by an ugly fact.
Your theory is crazy, but it's not crazy enough to be true.
Land: A part of the earth's surface, considered as property. The theory that land is property subject to private ownership and control is the foundation of modern society, and is eminently worthy of the superstructure.
Let your religion be less of a theory and more of a love affair.
Creationists make it sound as though a 'theory' is something you dreamt up after being drunk all night.
I have just got a new theory of eternity.
Einstein explained his theory to me every day, and on my arrival I was fully convinced that he understood it.
The knowledge of the theory of logic has no tendency whatever to make men good reasoners.
Religion is essentially the art and the theory of the remaking of man. Man is not a finished creation.
The theory that can absorb the greatest number of facts, and persist in doing so, generation after generation, through all changes of opinion and detail, is the one that must rule all observation.
An ounce of action is worth a ton of theory.
Thought and theory must precede all salutary action; yet action is nobler in itself than either thought or theory.
My theory has always been, that if we are to dream, the flatteries of hope are as cheap, and pleasanter, than the gloom of despair.
Experience without theory is blind, but theory without experience is mere intellectual play.