  The expression “binarium famosissimum” is not a medieval label for this pairing of doctrines; its use in this sense appears to be purely a twentieth-century development. Oddly enough, only a single occurrence of the expression has been found in a medieval text, the anonymous Summa philosophiae cited  above.[20]  But it clear that this author uses the expression to refer not to a pair of doctrines, whether to universal hylomorphism and plurality of forms or to any other pair, but to the division of substance into corporeal and  incorporeal[21]: