Tertullian

“ After two, multitude begins, now that one is exceeded. In short, we feel that reason herself expressly [3] forbids the belief in more gods than one, because the self-same rule lays down one God and not two, which declares that God must be a Being to which, as the great Supreme, nothing is equal; and that Being to which nothing is equal must, moreover, be unique. But further, what can be the use or advantage in supposing two supreme beings, two co-ordinate [4] powers? What numerical difference could there be when two equals differ not from one? ”

“ I would first ask, If there be two, why not more? Because if number be compatible with the substance of Deity, the richer you make it in number the better. Valentinus was more consistent and more liberal ”

“ Even if there were several equals, all would be just as much one, because, as equals, they would not differ one from another. So, if of two beings neither differs from the other, since both of them are on the supposition [5] supreme, both being gods, neither of them is more excellent than the other ”