It involves contemplative and Logical Reasoning, often supported by processes such as observation, experimentation, and research.
Theories can be scientific, falling within the realm of empirical and testable knowledge, or they may belong to non-scientific disciplines, such as philosophy, art, or sociology.
In modern science, the term "theory" refers to scientific theories, a well-confirmed type of explanation of nature, made in a way consistent with the scientific method, and fulfilling the criteria required by modern science.
Theories guide the enterprise of finding facts rather than of reaching goals, and are neutral concerning alternatives among values.
[a] The English word theory derives from a technical term in philosophy in Ancient Greek.
As an everyday word, theoria, θεωρία, meant "looking at, viewing, beholding", but in more technical contexts it came to refer to contemplative or speculative understandings of natural things, such as those of natural philosophers, as opposed to more practical ways of knowing things, like that of skilled orators or artisans.
In the book From Religion to Philosophy, Francis Cornford suggests that the Orphics used the word theoria to mean "passionate sympathetic contemplation".
[8] Pythagoras changed the word to mean "the passionless contemplation of rational, unchanging truth" of mathematical knowledge, because he considered this intellectual pursuit the way to reach the highest plane of existence.
[9] Pythagoras emphasized subduing emotions and bodily desires to help the intellect function at the higher plane of theory.
On the other hand, praxis involves thinking, but always with an aim to desired actions, whereby humans cause change or movement themselves for their own ends.
[c] Theories are analytical tools for understanding, explaining, and making predictions about a given subject matter.
A formal theory is syntactic in nature and is only meaningful when given a semantic component by applying it to some content (e.g., facts and relationships of the actual historical world as it is unfolding).
Theories may be expressed mathematically, symbolically, or in common language, but are generally expected to follow principles of rational thought or logic.
A pair of such theories is called indistinguishable or observationally equivalent, and the choice between them reduces to convenience or philosophical preference.
When theories are studied in mathematics, they are usually expressed in some formal language and their statements are closed under application of certain procedures called rules of inference.
Theories used in applications are abstractions of observed phenomena and the resulting theorems provide solutions to real-world problems.
This limitation, however, in no way precludes the construction of mathematical theories that formalize large bodies of scientific knowledge.
[citation needed] A theory that lacks supporting evidence is generally, more properly, referred to as a hypothesis.
Also, the theory that phlogiston is a substance released from burning and rusting material was eliminated with the new understanding of the reactivity of oxygen.
They are 'rigorously tentative', meaning that they are proposed as true and expected to satisfy careful examination to account for the possibility of faulty inference or incorrect observation.
[13]: 803 In science, the term "theory" refers to "a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.
Scientists use theories as a foundation to gain further scientific knowledge, as well as to accomplish goals such as inventing technology or curing diseases.
[17]From the American Association for the Advancement of Science: A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment.
In physics the term theory is generally used for a mathematical framework—derived from a small set of basic postulates (usually symmetries, like equality of locations in space or in time, or identity of electrons, etc.
At least some of the elementary theorems of a philosophical theory are statements whose truth cannot necessarily be scientifically tested through empirical observation.