a theory is a concept for the description of connections. In the logic a theory designates a deductive locked formula quantity.

The word theory (Greek theorein: observe, regard, [on] look; theoría: looking at, consideration, realization, the scientific view) designatedoriginally the view of the truth by pure thinking, independently of their realization.

The term is probably therefore used also indefinitely as opposite by practice.

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a theory sketches a picture (model) to the reality. It meets also a statement about the run of the world and is to that extent always a prognosis, which can be drawn by experiment to the account. The result of the experiment confirms (verified) or disproves (falsifiziert) a theory. Not falsifizierbare statements, z. B. a tautology or a definition, cannot doTheories its. One calls theoretically refutable acceptance, which are not yet experimentally decided, hypothesis. But, calls one would be potentially possible for theories, whose decision is foreseeable not possible after today's knowledge conditions, speculative and assigns her to the Parawissenschaften.Theories, which say something about the run of the world, without offering an experiment, it if necessary disproved - thus no statements of its a separating barness contain - are not part of the science: They can then either the Pseudowissenschaften, or the religion(or however the Esoterik) to be assigned. About a founded imbedding of the scientific theories into - according to the principle not scientific - more general ranges from realization the Metaphysik worries.

A theory must be sinnhaftig: the picture, itfrom the world gives, should to the regulations the logic and grammar correspond. Their truthfulness - that is in the modern understanding the compatibility - can thereafter however only by a comparison of the model, which gives her from the world, alsothe experiencable reality to be proven. In addition, the sciences reject theories, which are correct, but no particular use have (practicability), or are unnecessarily complicated (elegance principle).

Besides there is a strictly formal, also mathematically - logical Definition of the theory term: A quantity of T von Aussagen in a language is called a theory exactly if T is fulfillable and if each sentence, which follows from T, belongs already to T. Or more simply expressed: It must at all truelyto be can be round and in itself.

Further important characteristics are for example also the possibility of being able to indicate axioms for a theory as well as „the expression strength “of a theory: It is possible, the theory through finally/countable many axioms toodescribe, then it is called finally/countable axiomatisierbar. A theory is called (negation) completely exactly if each set of their underlying language or its negation is elements of the theory.

core elements

a theory consists of altogether three - indispensable - core elements:

  1. a system of statements about a certain cutout of the reality data concerning
  2. the conditions and the boundary conditions , by those, referred one on the other, these statements to apply are
  3. the possibility of forming hypotheses over future events and changes (prognosis - function)


  • physics: The forecasts of the classical mechanics and special relativity theory differ for example clearly, if the regarded objects move with speeds close of the speed of light.
    In the everyday life one cannot determine the differences, there the classical mechanics thatBorder line of special relativity theory is, if the speed is substantially smaller than the speed of light. Therefore the classical mechanics are in the everyday life the appropriate theory.
  • Geometry: To in each case straight line and one point, which are not on this straight line, givesit exactly one parallel by this point.This statement has one for a long time tried from the other axioms of geometry to conclude. Because one could show that to senseful models leads geometry, in which the parallel statement does not apply, hadone proved that the parallel statement is an axiom independent to the remaining geometry axioms (see non-Euclidean geometry).
  • Mathematics: The mathematician George CAN gate had a naive i.e. informal definition for the term quantity suggested. The theory resulting from it became of Bertrand Russell as widersprüchig proven with the Antinomie: The quantity of all quantities, which itself not when contain element. This “quantity” is a quantity in the sense of CAN gate. But the statement related to this quantity: This quantity is element of theireven a Antinomie places (descriptive well-known as Antinomie of the bar beer ). Nevertheless it is sufficient to work in school mathematics with this informal set theory. The mathematicians now usually use the formal theory of the Zermelo Fraenkel set theory, with which the problem that Compatibility was not solved, but was not made accessible for a mathematical treatment.
  • In the sociology became - for the social sciences generally - which develops concept of the theory of middle range.

A theory can be also a purely algorithmic procedure, like z. B.the planet theory for the computation of positions.

further aspects of the theory term

the methodical way, how theories come off, how thus the increase in knowledge takes place, are disputed.

In the development from theories becomes occasionally between induction, Deduction and Abduktion differentiated:

During the theory formation by induction one goes out with it that the scientist during the empirical process compiles data, in which finally internal structures and regularities becomes visible. Further positively running experiments are to confirm the theory and are the components of a verification (proof), which is to flow in the long run in nature-legal security (compatibility).
During the theory formation by deduction one assumes the scientist produces meaningful hypotheses, whose agreement with the data he examines afterwards by creative document. Further one Experiments must be undertaken with the serious goal of the Falsifikation (refutation). Only in the extent like theories work satisfactorily (the Falsifikation extract), can be won relative security.
The Abduktion closes of an available result and a possible or spontaneously formed Rule in a case. In order to make a surprising phenomenon explainable, a rule is hypothetically introduced, so that the result can be regarded as meaningful case of this rule. Abduktiv won realizations can be correct, must it however not.

In practicethe science mix inductive and deductive elements without problems, so that this question possesses more a science-theoretical and world-descriptive meaning.

The science with its theories offers a way to absolute truth or to a gradually taking place approximation to thoseTruth (which can however never be one most certainly) or is not truth not part of the sciences or actually gives it truth? The second, on Karl Popper decreasing/going back, position by the majority of the scientists one prefers at present, thosefirst applies - due to principleal realizations over observability - as if outdated.

In the colloquial language the term is understood usually in the sense about only one theory, and refers then only to particularly uncertain realizations. This does not have much with thatscientific definition from theory to to do, and leads unfortunately frequently to misunderstandings: For example the term relativity theory does not mean, as often (of non-scientists) falsely assumed that this is of particularly uncertain in the first senses. Of course is it principleal falsifizierbar, could thusdo not apply, but the partial word „- theory “means nothing over (Un) security in their contained statements, sonderen marks it as in itself conclusively and distinguishes it from the Newton's theory (classical Newton's mechanics).


itto the topic if theory gives numerous quotations, see in addition:

Wikiquote: Theory - quotations

see also

Wikiquote: Theory - quotations
Wiktionary: Theory - word origin, synonyms and translations


science theory

  • C. Thiel: Kind. Theory, in: Jürgen Mittelstrass(Hg.), encyclopedia philosophy and science theory, Bd. 4, Stuttgart/Weimar 1996, S. 260-270
  • R.N. Crave: Kind. Theories, in: W.H. Newton Smith (Hg.), A Companion ton the Philosophy OF Science. Blackwell Companions ton of Philosophy 18. Malden, measure. 2000, S. 515-524 (statement viewand non statement view of theories)
  • Helmut Seiffert/Gerhard Radnitzky: Hand encyclopedia of the science theory. German paperback publishing house (DTV) 1992. ISBN 3-423-04586-8
  • Wolfgang bar Mueller: Problems and results of the science theory and analytic philosophy. Volumes II/2-3. Berlin/Heidelberg/New York 1973/1986 (theory structure and theory dynamics; oft-quoted)
  • Wolfgang Balzer: The science and its methods. Principles of the science theory. A text book. Talking nonsense text book. Freiburg i.Br./München 1997 (relatively generally comprehensible introduction to the analytic science theory)
  • Wolfgang Balzer/C. Ulises Moulines/Joseph D. Sneed: At Architectonic for Science. The Structuralist Program. Reidel, Dordrecht 1987
  • Wolfgang Balzer/M. Heidelberger (Hgg.): To the logic of empirical theories. Berlin/New York 1983
  • Thomas's S. Boldly: The structure of scientific revolutions. stw 25. Frankfurt A.M. (1973) 2. Aufl. 1976 (classical book to the theory dynamics; describe irrational “paradigm changes”v.a. in the history of the natural sciences)
  • Theo A.F. Kuipers: Structures in Science. Heuristic Patterns Based on Cognitive Structures. At Advanced Textbook in Neo Classical Philosophy OF Science. Synthesis LIBRARY 301. Dordrecht among other things 2001 (fastidiously and detailled; analytic science theory)
  • Patrick Suppes:Representation and Invariance OF Scientific Structures. Stanford 2002
  • Peter V. Zima: What is theory? Theory term and dia.-logical theory in the culture and social sciences. UTB 2589. Tübingen and others 2004 (with ideology-critical emphasis)


  • Joachim knight: ThoseTheory of the origin and sense of the theory with Aristoteles, in: Publications of the working group for research of the country North Rhine-Westphalia, Geisteswissenschaften 1 (1953), S. 32-54.
  • Immanuel Kant: Over the common saying: That may be correct in the theory, is not suited however not forpractice. (1793). Newer casting in: Writings to historical philosophy, Immanuel Kant, Stuttgart 1985 (reclam).


  • Stephen Hawking: The pictorial short history of the time. ISBN 3-499-61487-1
  • briefly Lewin: Field theory in the social sciences.Berne, Stuttgart: Huber, 1963
  • R. Westermann: Science theory and experimental methodology. A text book to the psychological method teachings. Goettingen and others 2000 (well understandable application of the analytic science theory to the psychology)
  • Stephan chamber/Roger Lüdeke (Hgg.): Texts for the theory of the text. Reclam, Stuttgart 2005(Source texts to the text theory of Lotman, Barthes, Derrida, Bachtin, Ricoeur among other things)

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