Principle

Pronunciation

• IPA: /ˈprɪnsɪpÉ™l/, /ˈprɪnsÉ™pÉ™l/
• Hyphenation: prin + ci + ple
• Homophones: principal

Origin

From Old French principe, from Latin principium ("beginning, foundation"), from princeps ("first"); see prince.

Full definition of principle

Noun

1. A fundamental assumption.
• 2011-07-20, Edwin Mares, Propositional FunctionsLet 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.
2. We need some sort of principles to reason from.
3. 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.
4. (usually in the plural) Moral rule or aspect.
   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.
5. (physics) A rule or law of nature, or the basic idea on how the laws of nature are applied.
• 2013, Sarah Glaz, Ode to Prime Numbers, 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.
6. Bernoulli's principle;   The Pauli Exclusion Principle prevents two fermions from occupying the same state.   The principle of the internal combustion engine
7. A fundamental essence, particularly one producing a given quality.
• GregoryCathartine is the bitter, purgative principle of senna.
8. Many believe that life is the result of some vital principle.
9. (obsolete) A beginning.
• Edmund SpenserDoubting sad end of principle unsound.
10. A source, or origin; that from which anything proceeds; fundamental substance or energy; primordial substance; ultimate element, or cause.
• TillotsonThe soul of man is an active principle.
11. An original faculty or endowment.
• Stewartthose active principles whose direct and ultimate object is the communication either of enjoyment or suffering

Usage notes

Principle is always a noun ("moral rule"), but it is often confused with principal, which can be an adjective ("most important") or a noun ("school principal"). Consult both definitions if in doubt.

Incorrect usage:

He is the principle musician in the band

She worked ten years as school principle

A mnemonic to avoid this confusion is "The principal alphabetic principle places A before E".

Synonyms

• (moral rule or aspect) tenet

Derived terms

Related terms

• prince
• principal
• principality
• principled

Verb

1. (transitive) To equip with principles; to establish, or fix, in certain principles; to impress with any tenet or rule of conduct.
• L'EstrangeGovernors should be well principled.
• LockeLet an enthusiast be principled that he or his teacher is inspired.