theory

Meanings

1. 1
   noun

   a belief that can guide behavior

   the architect has a theory that more is less

2. 2
   noun

   A description of an event or system that is considered to be accurate.

   As they encrease the hatred of vice in some, so doe they enlarge the theory of wickednesse in all.

3. 3
   noun

   A coherent statement or set of ideas that explains observed facts or phenomena and correctly predicts new facts or phenomena not previously observed, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc.

   In its most proper acceptation, theory means the completed result of philosophical induction from experience.

4. 4
   noun

   The underlying principles or methods of a given technical skill, art etc., as opposed to its practice.

   Lopukhov wrote a number of books and articles on ballet theory, as well as his memoirs.

5. 5
   noun

   A field of study attempting to exhaustively describe a particular class of constructs.

   Knot theory classifies the mappings of a circle into 3-space.

6. 6
   noun

   A set of axioms together with all statements derivable from them; or, a set of statements which are deductively closed. Equivalently, a formal language plus a set of axioms (from which can then be derived theorems). The statements may be required to all be bound (i.e., to have no free variables).

   A theory is consistent if it has a model.

7. 7
   noun

   The standardization and study of fixed sequences of moves, especially in the opening phase of a game.

   Near-synonym: joseki

8. 8
   noun

   a tentative insight into the natural world

Etymology

From Middle French théorie, from Late Latin theōria, from Ancient Greek θεωρία (theōría, “contemplation, divine perspective, speculation, a looking at, a seeking”), from θεωρέω (theōréō, “to look at, view, see, consider, examine”), from θεωρός (theōrós, “spectator”), from θέα (théa, “view, perspective, sight”) + ὁράω (horáō, “to see, look”) [i. e. θέαν ὁράω (théan horáō, “see, look at a view; survey + genitive”)].