In his commentary on ST 1. q. 39 a. 1, Cajetan gives an argument from Scotus against Thomas’s claim that the persons in God do not really differ from the divine essence.
Concerning this claim the relations, or the the persons, do not differ from the divine essence as to the thing but only in ratio, several objections of Scotus arise in I Disputatio q. 4, for he wants it to be the case that person and essence are distinguished without any act of the intellect… The first reason is this: setting aside any act of the intellect, the Father has a communicable and an uncommunicable being according to the thing he is, therefore he ha sin himself a diversity of formal ratios. Because if there were something of only one ratio in him, it would either be simply communicable or simply incommunicable, and both are heretical. The second reason is that the Father, prior to anything we might say about his origin, either understands his essence and paternity as two objects formally distinct, or not. If so, then the point is proven, because a cognitive intuition is of the thing so far as the thing is present to it; if not then they are distinguished only according to the mode of conceiving, therefore the distinction between them is not that this thing is communicable, and that is incommunicable. The conclusion follows from the fact that a distinction that is only in ratio makes no difference as to what the thing itself is.
VI. Circa illam propositionem, relatio, seu persona, non differt re, sed ratione tantum, ab essentia divina, occurrunt obiectiones Scoti, in I, dist. ii, qu. iv. Vult enim quod persona et essentia distinguantur sine omni actu intellectus... Prima ratio est. Pater, secluso actu intellectus, habet in re entitatem communicabilem et entitatem incommunicabilem: ergo habet in se rem diversarum ratignura formalium…quia si esset res unius rationis in se, vel esset tantum communicabilis, vel tantum incomunicabilis; quorum utrumque est haereticum. Secunda ratio est. Pater, intelligens in prirao signo originis se , aut intelligit essentiara et paternitatera ut duo obiecta formaliter distincta, aut non. Si sic, habetur intentura : quia cognitio intuitiva est rei secundura esse praesens in se. Si non , ergo distinguuntur tantum in modo concipiendi: ergo ex distinctione inter ea non est hoc coramunicabile, et hoc incommunicabile. – Et tenet sequela: quia distinctio secundum modum concipiendi , nihil facit in re.
Cajetan sets down this principle in response to Scotus, from which his response is pretty easy to infer:
In God, according to the thing that he is and in the real order, there is one thing neither purely absolute or purely relative, neither mixed nor composite or resulting from both, but eminently and formally having what is relative (and even of many relative things) and what is absolute, and so also in the formal order or the ratio of many forms. Of himself, and not just in a way that arises due to our speaking about this, there is one unified formal ratio in God, neither purely absolute nor purely relative, neither purely communicable nor purely incommunicable, but eminently and formally containing both what is of absolute perfection, and whatever is required for the trinitarian relations. And it is necessary that this be the case: for it is necessary that whatever is most simple in itself be maximally one, and that one adequate formal ratio correspond to it, otherwise there would not be one thing that was per se and commensurately universal intelligible by which everything is known.
We err when, setting down the division between the absolute and relative as a principle, we imagine that this distinction between the absolute and relative is somehow prior to God; and that we consequently believe that we must place him in on one side of the distinction or the other. He is both opposites, since God is prior to being and to any of its oppositions: he is above being, above one, etc.
in Deo, secundum rera sive in ordine reali, est una res non pure absoluta nec pure respectiva, nec raixta aut composita aut resultans ex utraque ; sed eminentissirae et formaliter habens quod est respectivi (imo raultarura rerum respectivarum) et quod est absoluti : ita in ordine forraali seu rationura formalium, secundum se, non quoad nos loquendo, est in Deo unica ratio formalis , non pure absoluta nec pure respectiva, non pure communicabilis nec pure incommunicabilis; sed erainentissime ac formaliter continens et quidquid absolutae perfectionis est, et quidquid trinitas respectiva exigit. Oportet autem sic esse, quia oportet cuilibet siraplicissiraae rei secundura se maxirae uni, respondere unam adaequatam rationem formalem: alioquin non esset per se primo unum intelligibile a quovis intellectu…
Fallimur autem, ab absolutis et respectivis ad Deum procedendo, eo quod distinctionera inter absolutum et respectivura quasi priorem re divina imaginaraur ; et consequenter illam sub altero membro oportere poni credimus.
Et tamen est totum oppositum. Quoniam res divina prior est ente et omnibus differentiis eius: est enim super ens et super unum, etc.
Just Thomism 
faber said,
June 2, 2011 at 1:34 pm
The reference to Scotus should be as I Sent. d. 2 q. 4 or as it is found in the modern edition, Ord. I d. 2 qq.1-4 (ed. Vat. 2, ##-##).
I wonder what Cajetan would make of Aquinas’ account in scriptum I d.33-34 where he posits the fathers personal property as a distinct ratio from the ratio of the divine essence, and specifies the sense of ratio he has in mind as not fabricated by the soul. But ‘not fabricated by the soul’ is just what Scotus means by ‘real’. Whence I am tempted to agree with Francis of Meyronnes that Thomist rationes are roughly equivalent to Scotist formalitates. This shouldn’t suprise us much, since Franciscans were forbidden to read Aquinas’ Summa, but could read his Scriptum.