Try Our Apps


Avoid these words. Seriously.

petitio principii

[pi-tish-ee-oh prin-sip-ee-ahy; Latin pe-tee-ti-oh pring-kip-i-ee] /pɪˈtɪʃ iˌoʊ prɪnˈsɪp iˌaɪ; Latin pɛˈti tɪˌoʊ prɪŋˈkɪp ɪˌi/
noun, Logic.
a fallacy in reasoning resulting from the assumption of that which in the beginning was set forth to be proved; begging the question.
Origin of petitio principii
1525-35; < Medieval Latin petītiō prīncipiī, translation of Greek tò en archêi aiteîsthai the assumption at the outset Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for petitio principii
Historical Examples
  • Note the petitio principii in the use of the word "drugged."

    Tobacco and Alcohol John Fiske
  • For if not, it is merely a petitio principii, and a somewhat wide one.

  • The like will be the case, if the petitio principii is in the minor premiss and not in the major.

    Aristotle George Grote
  • Brown saw that there would be a petitio principii if it were.

  • There is nothing in this objection also, for it rests on a petitio principii.

  • So naked and unashamed an example of petitio principii would disgrace a debater in a pinafore.

  • This chapter, in which Aristotle declares the nature of petitio principii, is obscure and difficult to follow.

    Aristotle George Grote
  • You have committed a petitio principii;12 you have assumed in your minor premiss the very point to be demonstrated.

    Aristotle George Grote
  • He admits that he cannot demonstrate the Maxim against them, and that any attempt to do this would involve petitio principii.

    Aristotle George Grote
  • Whatever we receive intuitively, we receive without proof; and stated as a naked proposition, it must involve a petitio principii.

    Short Studies on Great Subjects James Anthony Froude
British Dictionary definitions for petitio principii

petitio principii

/pɪˈtɪʃɪˌəʊ prɪnˈkɪpɪˌaɪ/
(logic) a form of fallacious reasoning in which the conclusion has been assumed in the premises; begging the question Sometimes shortened to petitio
Word Origin
C16: Latin, translation of Greek to en arkhei aiteisthai an assumption at the beginning
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source

Word of the Day

Nearby words for petitio principii

Word Value for petitio

Scrabble Words With Friends