petitio principii

[ pi-tish-ee-oh prin-sip-ee-ahy; Latin pe-tee-ti-oh pring-kip-i-ee ]

noun

, Logic.

1. a fallacy in reasoning resulting from the assumption of that which in the beginning was set forth to be proved; begging the question.

petitio principii

/ pɪˈtɪʃɪˌəʊ prɪnˈkɪpɪˌaɪ /

noun

1. logic a form of fallacious reasoning in which the conclusion has been assumed in the premises; begging the question Sometimes shortened topetitio

Word History and Origins

Origin of petitio principii¹

1525–35; < Medieval Latin petītiō prīncipiī, translation of Greek tò en archêi aiteîsthai the assumption at the outset

Word History and Origins

Origin of petitio principii¹

C16: Latin, translation of Greek to en arkhei aiteisthai an assumption at the beginning

Example Sentences

Is it not then a petitio principii to say, that the fact ought to be disbelieved because the induction opposed to it is complete?

From Project Gutenberg

The following are additional instances of Petitio Principii, under more or less of disguise.

From Project Gutenberg

But if the words are cited as the proof, it would be a clear petitio principii, though there had been nothing else against it.

From Project Gutenberg

For if not, it is merely a petitio principii, and a somewhat wide one.

From Project Gutenberg

And then the declivity is slippery and at each instant there is risk of a fall into petitio principii.

From Project Gutenberg