Scientific theory, Theory of everything, Game theory, String theory, Horseshoe Theory, Theory of relativity, M-theory, Music theory, Miasma theory, The Big Bang Theory, Conspiracy theory, Recapitulation theory, Graph theory, Theory of Colours, Probability theory, Superstring theory, Social cognitive theory, Decision theory, Euler–Bernoulli beam theory, Colour theory, Set theory, Timoshenko–Ehrenfest beam theory, Systems theory, The Theory of Moral Sentiments, Sociocultural theory, Information theory, Chaos theory, Algebraic number theory, Number theory, Quantum theory, Analytic number theory, Ramsey theory, Double genocide theory, Social choice theory, Architectural theory, Hybrid Theory, Phlogiston theory, The Theory of Everything (2014 movie), Kinetic theory, Ring theory, Naive set theory

Theory of computation, Dynamical systems theory, Modern Monetary Theory, Game (game theory), Control theory, Cell theory, James–Lange theory, John Dalton, Theory of Good Human Nature, Penny (The Big Bang Theory), Critical race theory, Domino theory, Christ myth theory, Marlovian theory, DNA damage theory of ageing, Action theory, Theory of mind, Knot theory, Classical field theory, Atomic theory, Realism theory, Gateway drug theory, Class (set theory), Group theory, KK theory, Automata theory, Grand unification theory, White genocide myth, Reception theory, Embodiment theory, Category theory, Approximation theory, Zermelo–Fraenkel set theory, Crystal field theory, Computational complexity theory, Glottalic theory, Field (physics), Chemtrail conspiracy theory, Wheel theory, Communication Theory of Secrecy Systems, Selectorate theory, Screw theory, Theory of the Earth, Cultural Marxism conspiracy theory, Two-nation theory, Big Bang, Brønsted–Lowry acid–base theory, Combinatorial game theory, The Theory of Communicative Action, Decidability theory

Scientific theory, Theory of everything, Game theory, String theory, Horseshoe Theory, Theory of relativity, M-theory, Music theory, Miasma theory, The Big Bang Theory, Conspiracy theory, Recapitulation theory, Graph theory, Theory of Colours, Probability theory, Superstring theory, Social cognitive theory, Decision theory, Euler–Bernoulli beam theory, Colour theory, Set theory, Timoshenko–Ehrenfest beam theory, Systems theory, The Theory of Moral Sentiments, Sociocultural theory, Information theory, Chaos theory, Algebraic number theory, Number theory, Quantum theory, Analytic number theory, Ramsey theory, Double genocide theory, Social choice theory, Architectural theory, Hybrid Theory, Phlogiston theory, The Theory of Everything (2014 movie), Kinetic theory, Ring theory, Naive set theory, Theory of computation, Dynamical systems theory, Modern Monetary Theory, Game (game theory), Control theory, Cell theory, James–Lange theory, John Dalton, Theory of Good Human Nature, Penny (The Big Bang Theory), Critical race theory, Domino theory, Christ myth theory, Marlovian theory, DNA damage theory of ageing, Action theory, Theory of mind, Knot theory, Classical field theory, Atomic theory, Realism theory, Gateway drug theory, Class (set theory), Group theory, KK theory, Automata theory, Grand unification theory, White genocide myth, Reception theory, Embodiment theory, Category theory, Approximation theory, Zermelo–Fraenkel set theory, Crystal field theory, Computational complexity theory, Glottalic theory, Field (physics), Chemtrail conspiracy theory, Wheel theory, Communication Theory of Secrecy Systems, Selectorate theory, Screw theory, Theory of the Earth, Cultural Marxism conspiracy theory, Two-nation theory, Big Bang, Brønsted–Lowry acid–base theory, Combinatorial game theory, The Theory of Communicative Action, Decidability theory, Hybrid Theory EP, Loop (graph theory), Galois theory, History of the Big Bang theory, Smiley face murder theory, Theory Dasbien, Mutualism (economic theory), Economy-of-effort theory, Uses and gratifications theory, Third International Theory, Unification, Black swan theory, Computability theory, Critical theory, Cattell–Horn–Carroll theory, Theory of Evil Human Nature, Arrhenius acid-base theory, Secular Shrine Theory, Germ theory of disease, Trait theory, Algorithmic information theory, Pizzagate conspiracy theory, Moon landing conspiracy theories, Lewis acid-base theory, Coding theory, Theory of forms, Old quantum theory, R/K selection theory, Theory of a Deadman, The Assault on Truth: Freud's Suppression of the Seduction Theory, Ideal (ring theory), Information entropy, Elliott wave theory, Social comparison theory, Gesell's Maturational Theory, The Genetical Theory of Natural Selection, Order theory, The Big Bang Theory season 1, VSEPR theory, Judeo-Masonic conspiracy theory, The General Theory of Employment, Interest, and Money, General relativity, Lagrange's theorem (group theory), Set, Freud's psychoanalytic theories, Psychoanalysis, Clinton body count conspiracy theory, Jurisprudence, Endosymbiosis, Sahara pump theory, Special relativity, Four temperaments, Plate tectonics, Infant attachment, Graph (mathematics), Evolution, Quantum mechanics, Mars ocean theory, Archimedes' principle, Styx (band)