Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “first principles”

first principles

noun [plural]     UK
the basic and most important reasons for doing or believing something: We seem to have forgotten why we're fighting this campaign - we really need to return to first principles.Motives and reasons
(Definition of first principles noun from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of first principles

Browse related topics

You are looking at an entry to do with Motives and reasons, but you might be interested in these topics from the Behaving and interacting topic area:

Translations of “first principles”

Word of the Day

friendship

a situation in which two people are friends

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More