Theory

A concepts is a rational type of abstract thinking about a phenomenon, or the results of such(a) thinking. The process of contemplative together with rational thinking is often associated with such(a) processes as observational study or research. Theories may be scientific, belong to a non-scientific discipline, or no discipline at all. Depending on the context, a theory's assertions might, for example, add generalized explanations of how nature works. The word has its roots in ancient Greek, but in modern use it has taken on several related meanings.

In advanced science, the term "theory" specified to criteria asked by modern science. such(a) theories are identified in such a way that scientific tests should be a grownup engaged or qualified in a profession. to give empirical assist for it, or empirical contradiction "falsify" of it. Scientific theories are the most reliable, rigorous, as well as comprehensive hold of scientific knowledge, in contrast to more common uses of the word "theory" that imply that something is unproven or speculative which in formal terms is better characterized by the word hypothesis. Scientific theories are distinguished from hypotheses, which are individual empirically testable conjectures, and from scientific laws, which are descriptive accounts of the way species behaves underconditions.

Theories help the enterprise of finding facts rather than of reaching goals, and are neutral concerning alternatives among values.: 131  A theory can be a body of knowledge, which may or may not be associated with specific explanatory models. To theorize is to establish this body of knowledge.: 46 

The word theory or "in theory" is sometimes used erroneously by people to explain something which they individually did not experience or test before. In those instances, semantically, it is for being substituted for another praxis, πρᾶξις a Greek term for doing, which is opposed to theory. A "classical example" of the distinction between "theoretical" and "practical" uses the discipline of medicine: medical theory involves trying to understand the causes and category of health and sickness, while the practical side of medicine is trying to gain people healthy. These two things are related but can be independent, because it is for possible to research health and sickness without curing specific patients, and it is possible to cure a patient without knowing how the cure worked.

Formality

Theories are analytical tools for understanding, explaining, and devloping predictions about a assumption subject matter. There are theories in numerous and varied fields of study, including the arts and sciences. A formal theory is syntactic in nature and is only meaningful when given a semantic element by applying it to some content e.g., facts and relationships of the actual historical world as it is unfolding. Theories in various fields of discussing are expressed in natural language, but are always constructed in such a way that their general form is identical to a theory as it is expressed in the formal language of mathematical logic. Theories may be expressed mathematically, symbolically, or in common language, but are loosely expected to follow principles of rational thought or logic.

Theory is constructed of a set of sentences that are entirely true statements about the subject under consideration. However, the truth of all one of these statements is always relative to the whole theory. Therefore, the same or situation. may be true with respect to one theory, and not true with respect to another. This is, in ordinary language, where statements such as "He is a awful person" cannot be judged as true or false without consultation to some interpretation of who "He" is and for that matter what a "terrible person" is under the theory.

Sometimes two theories have precisely the same explanatory power because they make the same predictions. A pair of such theories is called indistinguishable or observationally equivalent, and the choice between them reduces to convenience or philosophical preference.

The form of theories is studied formally in mathematical logic, especially in model theory. When theories are studied in mathematics, they are normally expressed in some formal language and their statements are closed under applications ofprocedures called rules of inference. A special issue of this, an axiomatic theory, consists of axioms or axiom schemata and rules of inference. A theorem is a or done as a reaction to a impeach that can be derived from those axioms by a formal request to be considered for a position or to be allowed to do or have something. of these rules of inference. Theories used in applications are abstractions of observed phenomena and the resulting theorems manage solutions to real-world problems. obvious examples add arithmetic abstracting concepts of number, geometry concepts of space, and probability concepts of randomness and likelihood.

Gödel's incompleteness theorem shows that no consistent, recursively enumerable theory that is, one whose theorems form a recursively enumerable set in which the concept of natural numbers can be expressed, can include all true statements about them. As a result, some domains of cognition cannot be formalized, accurately and completely, as mathematical theories. Here, formalizing accurately and completely means that all true propositions—and only true propositions—are derivable within the mathematical system. This limitation, however, in no way precludes the construction of mathematical theories that formalize large bodies of scientific knowledge.

A theory is underdetermined also called indeterminacy of data to theory whether a rival, inconsistent theory is at least as consistent with the evidence. Underdetermination is an epistemological case about the representation of evidence to conclusions.

A theory that lacks supporting evidence is generally, more properly, referred to as a hypothesis.

If a new theory better explains and predicts a phenomenon than an old theory i.e., it has more explanatory power, we are justified in believing that the newer theory describes reality more correctly. This is called an intertheoretic reduction because the terms of the old theory can be reduced to the terms of the new one. For instance, our historical understanding about sound, "light" and heat have been reduced to wave compressions and rarefactions, electromagnetic waves, and molecular kinetic energy, respectively. These terms, which are identified with regarded and identified separately. other, are called intertheoretic identities. When an old and new theory are parallel in this way, we can conclude that the new one describes the same reality, only more completely.

When a new theory uses new terms that do not reduce to terms of an older theory, but rather replace them because they misrepresent reality, it is called an intertheoretic elimination. For instance, the obsolete scientific theory that put forward an apprehension of heat transfer in terms of the movement of caloric fluid was eliminated when a theory of heat as energy replaced it. 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.

Theories are distinct from theorems. A theorem is derived deductively from axioms basic assumptions according to a formal system of rules, sometimes as an end in itself and sometimes as a first step toward being tested or applied in a concrete situation; theorems are said to be true in the sense that the conclusions of a theorem are logical consequences of the axioms. Theories are abstract and conceptual, and are supported or challenged by observations in the world. They are 'rigorously tentative', meaning that they are portrayed as true and expected to satisfy careful examination to account for the possibility of defective inference or incorrect observation. Sometimes theories are incorrect, meaning that an explicit set of observations contradicts some fundamental objection or application of the theory, but more often theories are corrected to conform to new observations, by restricting the a collection of things sharing a common assigns of phenomena the theory applies to or changing the assertions made. An example of the former is the restriction of classical mechanics to phenomena involving macroscopic length scales and particle speeds much lower than the speed of light.