• WordNet 3.6
    • n theory a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena "a scientific hypothesis that survives experimental testing becomes a scientific theory","he proposed a fresh theory of alkalis that later was accepted in chemical practices"
    • n theory a belief that can guide behavior "the architect has a theory that more is less","they killed him on the theory that dead men tell no tales"
    • n theory a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena "theories can incorporate facts and laws and tested hypotheses","true in fact and theory"
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: Poor whites in Florida and Georgia are called "crackers." They got the name from their principal staple food, cracked corn. Another theory states that the name comes from the days when they would drive cattle southward using the "crack" of their bullwhips to keep the animals in line and moving.
    • Theory A doctrine, or scheme of things, which terminates in speculation or contemplation, without a view to practice; hypothesis; speculation.
    • Theory An exposition of the general or abstract principles of any science; as, the theory of music.
    • Theory The philosophical explanation of phenomena, either physical or moral; as, Lavoisier's theory of combustion; Adam Smith's theory of moral sentiments.
    • Theory The science, as distinguished from the art; as, the theory and practice of medicine.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: Rene Descartes came up with the theory of coordinate geometry by looking at a fly walk across a tiled ceiling.
    • n theory At this point we may again for a moment turn aside to consider the so-called Conscious Automaton Theory.
    • n theory Contemplation.
    • n theory Perception or consideration of the relations of the parts of an ideal construction, which is supposed to render completely or in some measure intelligible a fact or thing which it resembles or to which it is analogous; also, the ideal construction itself. Thus, political economists, in order to explain the phenomena of trade, suppose two or three men, actuated by calculation of interests alone, to be placed on a desert island, or some other simple situation. The perception of how such men would behave constitutes a theory which will explain some observed facts. In precisely the same way, an engineer who has to build a machine or a bridge imagines a structure much more simple than that which he is to make, and from the calculation of the forces and resistances of the ideal structure, which is theory, infers what will best combine economy with strength in the real structure.
    • n theory An intelligible conception or account of how something has been brought about or should be done. A theory, in this sense, will most commonly, though not always, be of the nature of a hypothesis; but with good writers a mere conjecture is hardly dignified by the name of a theory. Theory is often opposed to fact, as having its origin in the mind and not in observation.
    • n theory Plan or system; scheme; method.
    • n theory In mathematics, a series of results belonging to one subject and going far toward giving a unitary and luminous view of that subject: as, the theory of functions.
    • n theory Specifically, in music, the science of composition, as distinguished from practice, the art of performance.
    • ***
Chambers's Twentieth Century Dictionary
  • Interesting fact: When Charles Darwin published his theory on human evolution in The Descent of Man in 1871, not a single fossil that was known to be pre-human had been found to back up his ideas. Although his theory was later proved to be true, it was formulated entirely without physical evidence and based almost completely on speculation.
    • Theory an explanation or system of anything: an exposition of the abstract principles of a science or art: speculation as opposed to practice
    • ***


  • Friedrich Engels
    Friedrich Engels
    “An ounce of action is worth a ton of theory.”
  • Malcolm Muggeridge
    “One of the stupidest theories of Western life.”
  • Cadman
    “A little experience often upsets a lot of theory.”
  • Albert Einstein
    “If the facts don't fit the theory, change the facts.”
  • Samuel Johnson
    “All theory is against freedom of the will; all experience for it.”
  • H. L. Mencken
    “Morality is the theory that every human act must be either right or wrong, and that 99 % of them are wrong.”


Webster's Revised Unabridged Dictionary
F. théorie, L. theoria, Gr. a beholding, spectacle, contemplation, speculation, fr. a spectator, to see, view. See Theater
Chambers's Twentieth Century Dictionary
Gr. theōrēmatheōrein, to view—theasthai, to see.


In literature:

By the study of theory supplemented by the experimental application of theory to practice, as by drawing, design, etc.
"College Teaching" by Paul Klapper
Undemonstrated and undemonstrable theory?
"Carmen Ariza" by Charles Francis Stocking
Facts do not confirm the theory.
"Hours in a Library" by Leslie Stephen
Give the theory for the formation of carbonic acid and watery vapor thrown out of the system.
"A Treatise on Anatomy, Physiology, and Hygiene (Revised Edition)" by Calvin Cutter
It is a theory of process and not a theory of creation.
"History of Human Society" by Frank W. Blackmar
A general theory of catalytic phenomena does not at present exist.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1" by Various
He has perfected the theory of the military State, and he has acted consistently on the theory.
"German Problems and Personalities" by Charles Sarolea
The theory of nationality is involved in the democratic theory of the sovereignty of the general will.
"The History of Freedom" by John Emerich Edward Dalberg-Acton
But this theory has not led to any effective treatment.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3" by Various
Also the objective theory of contract has undermined the very citadel of the will theory.
"An Introduction to the Philosophy of Law" by Roscoe Pound
The theory is that man originally expressed his deepest emotions about food, love, and war in dances.
"The Book of This and That" by Robert Lynd
The theory, however, like all theories, had its defects.
"The Perfume of Eros: A Fifth Avenue Incident" by Edgar Saltus
His own theory, or rather his theory as understood by the present writer, may be stated thus.
"Custom and Myth" by Andrew Lang
The resemblance of this primitive theory to modern theories of evolution is remarkable.
"A Critical History of Greek Philosophy" by W. T. Stace
And this truth is not at all a speculative, unpractical theory: it is vital.
"The Expositor's Bible: The Book of Exodus" by G. A. Chadwick
Poisson's theory admits of being modified so as to agree with the results of experiment.
"Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2" by Various
It was as good as a play to her, especially as good as a play which confirms all one's own theories of life.
"The Galaxy" by Various
How, except on the theory that she knew where her daughter was, had assisted in her disappearance and approved of it?
"That Affair at Elizabeth" by Burton E. Stevenson
The new product then fulfills the conditions of the old theory which demands metre or rhythm.
"The Literature of Ecstasy" by Albert Mordell
But by this theory they might have been created within the districts which they now occupy.
"The Religion of Geology and Its Connected Sciences" by Edward Hitchcock

In poetry:

In youth, it was a way I had
To do my best to please,
And change, with every passing lad,
To suit his theories.
"Indian Summer" by Dorothy Parker
Great Nature's hand, in every plan,
Had laid in wise design,
But what design, or use, is in
This theory of thine?
"A Thought Of Heaven" by Madge Morris Wagner
Like Georgia shining in her beauty,
Like a land of light by open seas,
It beckons-veiled within a mist
Of wild surmise and theories.
"Here—now—our age of socialism!..." by Boris Pasternak
They bring us the blessing of blessings,
Which few were looking to see —
A firm and unchangeable Union,
In fact, as in theory, free!
"Columbia's Guardian Angels" by Henry Clay Work
Up on the theory of flight.
Dear God of the wildness of poetry, let them mate
To the death in the rotten branches,
Let the tree sway and burst into flame
"For The Last Wolverine" by James Dickey
Night after night they argued how the kangaroo was born,
And each one held the other’s stupid theories in scorn,
Bill believed it was ‘born inside,’ Jim declared it was born out—
Each as to his own opinions never had the slightest doubt.
"Bill and Jim Fall Out" by Henry Lawson

In news:

The tides in human evolutionary theory began to shift, because it turns out bonobos are very much unlike chimps.
The Obama administration's theory of Middle East appears to have 'broken down completely'.
Lauren Gunderson's new play is more compelling in theory than in execution.
Here, we explain three new theories for how cancer may form.
Great ball of iron or theory full of hot air.
He mistakes a special for a general theory of the Obama presidency.
Conspiracy buffs don't let facts get in the way of a good conspiracy theory.
My post-IDSA conference thoughts lead me to believe that a serious body of thought and methodology is being built that is successfully challenging traditional management theory.
Two results from the beginning of the universe suggest that existing theories of it, though strange, are correct.
Economic theory suggests that when a major input cost goes up, the industry utilizing that input reduces its production.
New theories emerge about the long-ago collision that transformed our night sky.
After a half-century of watching television, I've finally got something to show for it — my very own theory.
Basic economic theory says that in a perfectly competitive market, rivals will eventually eat up any excess profits earned by a successful business.
Featured guest chef Anthony Suter, resident composer and music theory professor at the University of Redlands, will treat guests to a multicourse meal.
" Darwin and his theory are dead," says Mr Oktar, founder and honorary president of the Science Research Foundation, an Istanbul outfit dedicated to debunking the Victorian-era English naturalist.

In science:

String perturbation theory provides an effective description of these theories only is well described by 6 dimensional : theory.
OM Theory in Diverse Dimensions
Also considered are a new type of field theory, and indications from black hole physics and the cosmological constant problem that effective field theories may not completely describe theories of gravity.
The Utility of Quantum Field Theory
We also perturb the model to Nc = (2, 0) model and show that the partition function of the theory is sum of contributions of the generalized Donaldson-Witten theory in the previous section and a generalized version of Seiberg-Witten theory.
Higgs Bundles and Four Manifolds
These symmetries, and the fact that a large class of field theories can be formulated as decoupling limits of string theories, have been used to derive many examples of field theory dualities, as well as dual correspondences between field theories and supergravity theories.
Duality Cascade and Oblique Phases in Non-Commutative Open String Theory
Therefore, matrix string theory (or a two dimensional super Yang-Mills theory) can be considered as a microscopic description of the world volume theory of wrapped membranes in M theory.
Perturbative dynamics of matrix string for the membrane
The gauge theory versus string theory/gravity correspondence is a more precise indication that gravity can be realized as an effective theory of a four-dimensional gauge theory.
Holography and Brane-bulk Energy Exchange
Quantum theory is itself an outcome dependent theory so the possibility remains that—since quantum theory is itself a theory we use to predict the probabilities of unknown variables— quantum theory is its own ‘completion’.
Relationalism vs. Bayesianism
The theory has recently received widespread attention due to the fact that it arises naturally as the low energy limit of many theories of quantum gravity such as the supersymmetric string theory or the Kaluza-Klein theory and is also found to be consistent with present cosmological observations [2-7].
Brans-Dicke theory: Jordan vs Einstein Frame
Stable and o-minimal theories, as well as the theory of the p-adic field are all examples of theories with NIP, while simple unstable theories all have the independence property.
Groups, measures, and the NIP
This experimental signature distinguishes the doped-carrier theory from other candidate mean-field theories of high-Tc superconductors, like the slave-boson theory and the conventional BCS theory.
Electromagnetic response of high-Tc superconductors -- the slave-boson and doped-carrier theories
Many examples are provided, including classical descent theory, Hopf-Galois theory over Hopf algebras and Hopf algebroids, Galois theory for corings and group-corings, and MoritaTakeuchi theory for corings.
Galois theory in bicategories
For example abelian group theory, complete theory of finitely generated linear groups, and more generally the complete theory (or the universal theory) of a submodel of an ω -stable model.
On Finitely Generated Models of Theories with at Most Countably Many Nonisomorphic Finitely Generated Models
We discuss Vafa-Witten theory on ALE spaces, and embed the gauge theory into string theory as a worldvolume theory on top of D4-branes.
Topological Strings and Quantum Curves
Although stable theories were originally the main environment for studying forking, we saw subsequently the fundamental role of forking in simple theories, and more recently its importance for N I P theories, including ominimal theories and valued fields.
Generic stability, regularity, and quasiminimality
We show that the partition function of the random matrix theory coincides with the partition function of the finite-volume effective theory at high density, and that the LeutwylerSmilga-type spectral sum rules of the random matrix theory are identical to those derived from the effective theory.
Chiral random matrix theory for two-color QCD at high density