as well as Spanish probar 'to taste' (sometimes 'to touch' or 'to test'), Italian '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. It is likely that the idea of demonstrating a conclusion first arose in connection with geometry, which originated