Word.ws English Dictionary

petitio principii

UK/pɪˈtɪʃiˌəʊ prɪnˈkɪpiˌaɪ/US/pəˈtɪʃiˌoʊ prɪnˈsɪpiˌaɪ/

petitio principii noun: the logical fallacy of begging the question (i.e., "assuming the conclusion").

Noun

petitio principii

  1. (uncountable) The logical fallacy of begging the question (i.e., "assuming the conclusion").
  2. (countable) A particular argument which commits the fallacy of begging the question; a circular argument.
    • A somewhat similar objection has been made by Locke and others, to the effect that the ordinary demonstrative syllogism is a petitio principii.1869, C. S. Pierce, “Grounds of Validity of the laws of Logic: Further Consequences of Four Incapacities.”, in Journal of Speculative Philosophy
    • The Streitberg-Michels Theory is evidently a petitio principii. To explain ē in gēbum, it is from the outset taken for granted, for inadequate reasons of method, that the form must be a perfect. [italics original]1938, E. Prokosch, A Comparative Germanic Grammar

Origin of petitio principii

From Latin petītiō prīncipiī (literally “an assumption from the beginning”), calque of Ancient Greek τὸ ἐν ἀρχῇ αἰτεῖσθαι (tò en arkhēî aiteîsthai, “to assume from the beginning”).

Questions about petitio principii

What does petitio principii mean?
Petitio principii means the logical fallacy of begging the question (i.e., "assuming the conclusion").
What part of speech is petitio principii?
Petitio principii is a noun.
How do you pronounce petitio principii?
Petitio principii is pronounced /pɪˈtɪʃiˌəʊ prɪnˈkɪpiˌaɪ/ (UK).

Words near petitio principii in the dictionary

  1. Petitfreres
  2. petitgrain
  3. Petithomme
  4. Petithommes
  5. petitio
  6. petitio principii
  7. petition
  8. petition of right
  9. petitionable
  10. petitional
  11. petitionarily

Source and license

Adapted from Wiktionary: petitio principii (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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