Axiom of Maria is a precept in alchemy: "One becomes two, two becomes three, and out of the third comes the one as the fourth."[1] It is attributed to 3rd century alchemist Maria Prophetissa, also called Mary the Jewess,[2] sister of Moses, or the Copt.[3] A more detailed quote was provided by the seventh-century alchemistic author called Christianos, who cited that what Maria uttered was "One becomes two, two becomes three, and by means of the third and fourth achieves unity; thus two are but one".[4] Marie-Louise von Franz also gave an alternative version, which states: "Out of the One comes Two, out of Two comes Three, and from the Third comes the One as the Fourth."[5] The axiom served as a recurring theme associated with alchemy for over seventeen centuries.[6]