Tertullian, Against Marcion 5
What reason could possibly justify composing two supreme, supreme beings? First, I demand to know: why stop at two? If number suited the divine substance, it would be far more fitting to believe that substance is abundant. Valentinus was at least more honorable and generous in his invention: he dared to posit two primal principles, Bythos and Sigen, and then, like the sow of Aeneas, farrowed a litter of thirty Aeons, pouring out a whole swarm of divinity. But any logic that refuses to admit more than one supreme being also refuses to admit two, because it thereby admits a plurality. Once you pass one, you have entered the realm of number; one is, after all, a number. Whatever rationale could admit two could just as easily admit more. Two is already a multitude, unity already breached.
In our view, the force of this reasoning does not permit belief in many gods, and the very rule that establishes one God excludes two. For what must God be? A being to whom nothing is equal, so that He is supreme and greatest—yes, unique, because nothing equals Him. Now, if there are two supreme, supreme beings, two equals, to what task or profit would they be assigned? What difference does the number make when two equals are indistinguishable from one? The reality present in both is a single thing. Even if there were many equals, they would all amount to the same as one; they would effectively be one, since they do not differ from each other insofar as they are equals. Furthermore, if neither of the two surpasses the other—so that both are supreme, both are God, neither offers more than the other—they demonstrate no rationale for their own number. Lacking superiority, they fail the test: the number of the divine ought to rest on the highest reason, or else the very worship owed to it is dragged into uncertainty.
Consider the dilemma: faced with two gods as perfectly matched as two supreme beings, what am I to do? If I worship both, I fear the sheer volume of service would be judged superstition rather than religion, because I could earn the favor of both by honoring just one—a fact that itself testifies to their equality and unity, since in reverencing one I revere the other, and in the one I possess two. If I worship only one, I face the same scruple: I would seem to be pouring out the empty vanity of number without distinction, pointlessly. The safer conclusion: it is better to worship neither than to worship one with a divided heart or both in vain.
Latin
Aut quae ratio duo summa magna composuit? primo enim exigam, cur non plura, si duo, quando locupletiorem oporteret credi substantiam diuinitatis, si competeret ei numerus. honestior et liberalior Valentinus, qui simul ausus est duos concipere, Bython et Sigen, tum usque ad triginta Aeonum fetus, tamquam Aeneiae scrofae, examen diuinitatis effudit. quaecumque ratio plura summa magna non patitur admitti, eadem nec duo, ut (et) ipsa plura. [post unum] post ; unum enim numerus. quae potuit duo admittere, eadem potuit et plura. et duo enim multitudo, unione iam excessa. denique apud nos uis rationis istius ipso termino plures deos credi non sinit, quo nec duos illa regula unum deum sistens. i qua deum id esse oporteat, cui nihil adaequetur, ut summo i magno, unicum autem sit, cui nihil adaequetur. iam nunc i duo summa magna, duo paria, cui operae pretio, cui emolumento deputarentur? quid interfuit numeri, cum duo paria non differant uno? una enim res est, quae eadem in duobus est. etiamsi plura essent paria, tantundem omnia (quantum) ; unum fuissent, nullo inter se differendo, qua paria. porro si i neutrum ex duobus altero distat, ut ambo summa magna, qua dei ambo, neutrum plus altero praestat, nullam iam rationem numeri sui ostendunt, praestantiam non habentes, numerus autem diuinitatis summa ratione constare deberet, uel quoniam et cultura eius in anceps deduceretur. ecce enim duos intuens deos tam pares quam duo summa magna, quid facerem? si ambos colerem, uererer, ne abundantia officii superstitio potius quam religio existimaretur, quia duos tam pares et in altero ambos possem in uno demereri, hoc ipsum testimonio praestans parilitati et unitati eorum, dum alterum in altero uenerarer, dum in uno mihi duo sunt. si alterum colerem, aeque recogitarem, ne suffundere uiderer numeri uanitatem sine differentia superuacui, hoc est: tutius censerem neutrum colendum quam alterum cum scrupulo [colendum ] aut ambos uane.