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

British Dictionary definitions for petitio principii

petitio principii
/ (pɪˈtɪʃɪˌəʊ prɪnˈkɪpɪˌaɪ) /

noun

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 for petitio principii

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