 Related modern words are English "probe", "probation", and "probability", Spanish "probar" (to smell or taste, or sometimes touch or test), Italian "provare" (to try), and German "probieren" (to try).The legal term "probity" means authority or credibility, the power of testimony to prove facts when given by persons of reputation or status.Plausibility arguments using heuristic devices such as pictures and analogies preceded strict mathematical proof.