Theory
Theory is a generic term that generalizes the concept of thinking, or the results of thinking. A more specific definition of “theory” depends on the context, and the results might for example include generalized explanations of how nature works, or even how divine or metaphysical matters are thought to work.The word has its roots in ancient Greek: the word "theory" was used in Greek philosophy, for example, by Plato. It is a statement trying to explain how and why particular facts are related. It is related to words for θεωρός "spectator", θέα thea "a view" + ὁρᾶν horan "to see", literally "looking at a show" (see Greek Dictionary Headword).In modern use, theory has taken on several different related meanings.
In sciences, a scientific theory is a unifying and self-consistent explanation of fundamental natural processes or phenomena that is totally constructed of corroborated hypotheses (Schafersman, 1997). A theory, therefore, is built of reliable knowledge -built of scientific facts- and its purpose is to explain major natural processes or phenomena. Scientific theories explain nature by unifying many once-unrelated facts or corroborated hypotheses; they are the strongest and most truthful explanations of how the universe, nature, and life came to be, how they work, what they are made of, and what will become of them. Since humans are living organisms and are part of the universe, science explains all of these things about ourselves.
References:
Schafersman, Steven D. (1997), An Introduction to Science, Scientific Thinking and the Scientific Method, report of Department of Geology, Miami University January, 1997.