The mathematical framework of quantum theory has passed countless successful tests and is now universally accepted as a consistent and accurate description of all atomic phenomena.
Erwin Schrodinger

A mathematical theory is not to be considered complete until you have made it so clear that you can explain it to the first man whom you meet on the street.
David Hilbert

The further a mathematical theory is developed, the more harmoniously and uniformly does its construction proceed, and unsuspected relations are disclosed between hitherto separated branches of the science.
David Hilbert

All theory of modernity in sociology suggests that the more modernity there is, the less religion. In my theory we can realize that this is wrong: atheism is only one belief system among many.
Ulrich Beck

The knowledge of the theory of logic has no tendency whatever to make men good reasoners.
Thomas B. Macaulay

Scientific theory is a contrived foothold in the chaos of living phenomena.
Wilhelm Reich

Some people wish above all to conform to the rules, I wish only to render what I can hear. There is no theory. You have only to listen. Pleasure is the law.
Claude Debussy

But the scientific importance of a change in knowledge of fact consists precisely in j its having consequences for a system of theory.
Talcott Parsons

In so far as such a theory is empirically correct it will also tell us what empirical facts it should be possible to observe in a given set of circumstances.
Talcott Parsons

It is probably safe to say that all the changes of factual knowledge which have led to the relativity theory, resulting in a very great theoretical development, are completely trivial from any point of view except their relevance to the structure of a theoretical system.
Talcott Parsons

The implications of these considerations justify the statement that all empirically verifiable knowledge even the commonsense knowledge of everyday life - involves implicitly, if not explicitly, systematic theory in this sense.
Talcott Parsons

Theory not only formulates what we know but also tells us what we want to know, that is, the questions to which an answer is needed.
Talcott Parsons

But the fact a person denies that he is theorising is no reason for taking him at his word and failing to investigate what implicit theory is involved in his statements.
Talcott Parsons

You can't run a business or anything else on a theory.
Harold S. Geneen

While gossip among women is universally ridiculed as low and trivial, gossip among men, especially if it is about women, is called theory, or idea, or fact.
Andrea Dworkin

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

First literature came to refer only to itself, the literary theory.
Mason Cooley

If you start any large theory, such as quantum mechanics, plate tectonics, evolution, it takes about 40 years for mainstream science to come around. Gaia has been going for only 30 years or so.
James Lovelock

Life is so unlike theory.
Anthony Trollope

A young man is a theory, an old man is a fact.
Edgar Watson Howe