In the next place, we must speak of the triad, which is consubsistent with this mixture. For every mixture, if it is rightly made, as Socrates says, requires these three things, beauty, truth, and symmetry. For neither will any thing base, if it is introduced into the mixture, impart rectitude, since it will be the cause of error, and of inordinate prerogative, nor if truth is at any time separated, will it suffer the mixture to consist of things that are pure, and which are in reality subdued, but it will fill the whole with an image and with non-being. Nor without symmetry will there be a communion of the elements, and an elegant association. Symmetry, therefore, is necessary to the union of the things that are mingled, and to an appropriate communion. But truth is necessary to purity. And beauty to order; which also renders the whole lovely. For when each thing in the mixture has a place adapted to itself, it renders both the elements, and the arrangement resulting from them, beautiful. Here therefore, in the first mixture, these three things are apparent, symmetry, truth, and beauty. And symmetry indeed is the cause to the mixture, that being is one; truth is the cause of the reality of its existence; and beauty is the cause of its being intelligible. Hence it is intelligible and truly being. That also which is primarily being is more uniform, and intellect is conjoined to it, according to its familiarity with the beautiful. But each participates of existence, because it is being derived from being. That which is mixed however, is supreme among beings, because it is united to _the good_. And it appears to me, that the divine Iamblichus perceiving these three causes of being, defines the intelligible in these three, viz. in symmetry, truth, and beauty, and unfolds the intelligible Gods through these in the Platonic theology. In what manner indeed, the intelligible breadth consists of these, will be most evident as we proceed. Now however, from what has been said, it is perfectly manifest why Socrates says that this triad is found to be in the vestibules of the good. For that which is primarily being participates of this triad through its union with _the good_. For because indeed _the good_ is the measure of all beings, the first being becomes itself commensurate. Because the former is prior to being, the latter subsists truly and really. And because the former is good and desirable, the latter presents itself to the view as the beautiful itself. Here therefore, the first beauty also subsists; and on this account _the one_ is not only the cause of good, but likewise of beauty, as Plato says in his Epistles. Beauty however subsists here occultly, since this order comprehends all things uniformly, in consequence of subsisting primarily from the principles [bound and infinity]. But where and how beauty is unfolded into light, we shall shortly explain. CHAPTER XII.