An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Logic: The quality of an argument when its conclusion is false even if all the premises are true.

→ in-; → valid.

Lack of → validity.

→ invalid; → -ity.

Logic: Of an argument, if the premises are true, then the conclusion cannot be denied without contradiction. The truth of the premises logically guarantees the truth of the conclusion.

M.E., from M.Fr. valide, from L. validus "strong, effective," from valere "to be strong."

Pâymand, from pâ, pây "foot; base, foundation, firmness" (Mid.Pers. pâd, pây; Av. pad- "foot;" cf. Skt. pat; Gk. pos, genitive podos; L. pes, genitive pedis; P.Gmc. *fot; E. foot; Ger. Fuss; Fr. pied; PIE *pod-/*ped-) + -mand possession suffix.

Logic: Of an argument, whether or not the conclusion follows logically from the premises and the allowable syllogisms of the logical system being used.

Quality noun from → valid.