# principle
## English
### Etymology

From Middle English principle, from Old French principe, from Latin prīncipium (“beginning, foundation”), from prīnceps (“first”). By surface analysis, prīmus (“first”) +‎ -ceps (“catcher”); the former ultimately from Proto-Indo-European *preh₂- (“before”); see also prince.

### Pronunciation

* IPA: /ˈpɹɪnsɪpəl/, /ˈpɹɪnsəpəl/
* Audio (US):(file)
* Hyphenation: prin‧ci‧ple
* Homophone: principal

### Noun

principle (plural principles)
* A fundamental assumption or guiding belief.
    Synonym: premise
    We need some sort of principles to reason from.
** 2011 July 20, Edwin Mares, “Propositional Functions”, in The Stanford Encyclopedia of Philosophy, retrieved 2012-07-15:Let us consider ‘my dog is asleep on the floor’ again. Frege thinks that this sentence can be analyzed in various different ways. Instead of treating it as expressing the application of __ is asleep on the floor to my dog, we can think of it as expressing the application of the concept my dog is asleep on __ to the object the floor (see Frege 1919). Frege recognizes what is now a commonplace in the logical analysis of natural language. We can attribute more than one logical form to a single sentence. Let us call this the principle of multiple analyses. Frege does not claim that the principle always holds, but as we shall see, modern type theory does claim this.
* A rule used to choose among solutions to a problem.
    The principle of least privilege holds that a process should only receive the permissions it needs.
** 2009 September 22, Reuters, “F.C.C. Calls Open Internet Rules Vital”, in The New York Times‎:Mr. Genachowski proposed codifying the new principles with four existing principles issued several years ago by the F.C.C. They say that network operators cannot prevent users from accessing lawful Internet content, applications and services of their choice, nor can they prohibit users from attaching nonharmful devices to the network.
* (sometimes pluralized) Moral rule or aspect.
    Synonym: tenet
    I don't doubt your principles.
    You are clearly a person of principle.
    It's the principle of the thing; I won't do business with someone I can't trust.
** 1837, L[etitia] E[lizabeth] L[andon], “The Author and the Actress”, in Ethel Churchill: Or, The Two Brides. […], volume III, London: Henry Colburn, […], →OCLC, page 105:Lavinia—shrewd, careless, clever; ready to meet any difficulty, however humiliating, that might occur; utterly without principle; confident in that good fortune, which she scrupled at no means of attaining—was the very type of the real.
* (physics) A rule or law of nature, or the basic idea on how the laws of nature are applied.
    Bernoulli's principle
    The Pauli Exclusion Principle prevents two fermions from occupying the same state.
    The principle of the internal combustion engine
** 2013 July-August, Sarah Glaz, “Ode to Prime Numbers”, in American Scientist, volume 101, number 4:Some poems, echoing the purpose of early poetic treatises on scientific principles, attempt to elucidate the mathematical concepts that underlie prime numbers. Others play with primes’ cultural associations. Still others derive their structure from mathematical patterns involving primes.
* A fundamental essence, particularly one producing a given quality.
    Many believe that life is the result of some vital principle.
** A chemical compound within plant or animal tissue that is characteristic of it and more or less peculiar to it, such that it defines the character of that tissue from a human viewpoint (as for example nicotine in tobacco).
    the active principle
*** 1845, William Gregory, Outlines of Chemistry:Cathartine is the bitter, purgative principle of senna.
* A source, or origin; that from which anything proceeds; fundamental substance or energy; primordial substance; ultimate element, or cause.
** 1664, John Tillotson, “Sermon I. The Wisdom of Being Religious. Job XXVIII. 28.”, in The Works of the Most Reverend Dr. John Tillotson, Late Lord Archbishop of Canterbury: […], 8th edition, London: […] T. Goodwin, B[enjamin] Tooke, and J. Pemberton, […]; J. Round […], and J[acob] Tonson] […], published 1720, →OCLC:The soul of man is an active principle.
* An original faculty or endowment.
** 1828, Dugald Stewart, The Philosophy of the Active and Moral Powers of Man:those active principles whose direct and ultimate object is the communication either of enjoyment or suffering
* Misspelling of principal.
* (obsolete) A beginning.
** 1596, Edmund Spenser, “Book V, Canto IX”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC, stanza 2:Doubting sad end of principle unsound.

#### Usage notes

* Principle ("moral rule"), as a noun, is often confused with principal, which can be an adjective ("most important") or a noun ("school principal"). A memory aid to avoid this confusion is: "The principal alphabetic principle places A before E". Another well-known one often taught to schoolchildren is that the school principal is their pal (friend).

#### Derived terms

* acceleration principle
* agreement in principle
* Anna Karenina principle
* anthropic principle
* Archimedes' principle
* arm's length principle
* aufbau principle
* Babinet's principle
* BANANA principle
* Bernoulli's principle
* Bridlington principle
* Cavalieri's principle
* Chicago principles
* composite reuse principle
* cooperative principle
* Copernican principle
* Copernican time principle
* correspondence principle
* cosmological principle
* Courant minimax principle
* day-year principle
* dependency inversion principle
* desert principle
* Dilbert principle
* Dirichlet's box principle
* Dirichlet's drawer principle
* dormitive principle
* equivalence principle
* extractive principle
* Fermat's principle
* Fermat's principle of least time
* Fick principle
* first principle
* first principles
* four-eye principle
* Franck-Condon principle
* Goldilocks principle
* Haldane principle
* handicap principle
* Hardy-Weinberg principle
* harm principle
* Heisenberg principle
* Heisenberg uncertainty principle
* Hollywood principle
* holographic principle
* Huygens-Fresnel principle
* Huygens' principle
* IBM Pollyanna Principle
* indeterminacy principle
* in principle
* interface segregation principle
* Kerckhoffs's principle
* KISS principle
* Landauer's principle
* Le Châtelier's principle
* Le Chatelier's principle
* life/dinner principle
* life-dinner principle
* Liskov substitution principle
* Lotus principle
* Mach's principle
* matter of principle
* Matthew principle
* MAYA principle
* mediocrity principle
* metaprinciple
* Micawber principle
* Mitchell principle
* non-aggression principle
* nonaggression principle
* Novikov self-consistency principle
* on principle
* open/closed principle
* open-closed principle
* Pareto principle
* parsimony principle
* Pauli exclusion principle
* Peter Parker principle
* Peter principle
* pigeonhole principle
* Planck's principle
* pleasure principle
* polluter pays principle
* precautionary principle
* principled
* principle of charity
* principle of contradiction
* principle of excluded middle
* principle of explosion
* principle of indifference
* principle of insufficient reason
* principle of least action
* principle of least astonishment
* principle of least knowledge
* principle of least surprise
* principle of least time
* principle of legality
* principle of locality
* principle of parsimony
* principle of Pseudo-Scotus
* principle of relativity
* principle of substitutivity
* principle of sufficient reason
* principle of verifiability
* principle of verification
* proximate principle
* Q-principle
* reality principle
* rebus principle
* reciprocity principle
* Ritz's combination principle
* Robbins principle
* R-principle
* Rydberg-Ritz combination principle
* Sandford principle
* Scheimpflug principle
* sector principle
* Shirky principle
* single responsibility principle
* Smurfette principle
* Spider-Man principle
* strong equivalence principle
* superposition principle
* uncertainty principle
* verifiability principle
* verification principle
* vicious circle principle

#### Related terms

* prince
* principal
* principality

#### Translations

    The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

### Verb

principle (third-person singular simple present principles, present participle principling, simple past and past participle principled)
* (transitive) To equip with principles; to establish, or fix, in certain principles; to impress with any tenet or rule of conduct.
** 1689 (indicated as 1690), [John Locke], chapter 4, in An Essay Concerning Humane Understanding. […], London: […] Eliz[abeth] Holt, for Thomas Basset, […], →OCLC, book I, page 20:Let an enthusiast be principled that he or his teacher is inspired.

#### Further reading

* “principle”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
* William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “principle”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.