phrase/le fɛ sɔ̃ tɛ.ty/
the facts of a matter are clear and unavoidable; the writing is on the wall
“N'en doutons pas, comme toutes les théories fausses du passé, cette doctrine finira par être balayée par les faits, car les faits sont têtus.” — Let's not doubt that, like all the old false theories, this doctrine will end up being sweep aside by the facts, because facts are stubborn.
From a translation of a quote by Mark Twain: facts are stubborn things, but statistics are pliable (les faits sont têtus, mais les statistiques sont souples). First used in its current sense in a French translation of Vladimir Lenin's Materialism and Empirio-criticism.