Yes. The intellect is a passive power and it is evident that with us to understand is "in a way to be passive" because whatever passes from potentiality to act, may be said to be passive, even when it is perfected.
Intellectus est potentia passiva et patet quod intelligere nostrum est quoddam pati quia omne quod exit de potentia in actum, potest dici pati, etiam cum perficitur.
The agent is nobler than the patient, if the action and the passion are referred to the same thing; but not always, if they refer to different things. Now the intellect is a passive power in regard to the whole of universal being; while the vegetative power is active in regard to some particular being, namely, the body as united to the soul. Wherefore nothing prevents such a passive force being nobler than such an active one.
Agens est nobilius patiente, si ad idem actio et passio referantur; non autem semper, si ad diversa. Intellectus autem est vis passiva respectu totius entis universalis. Vegetativum autem est activum respectu cuiusdam entis particularis, scilicet corporis coniuncti. Unde nihil prohibet huiusmodi passivum esse nobilius tali activo.
The intellect, as we have seen above (Q78, A1), has an operation extending to universal being. We may therefore see whether the intellect be in act or potentiality by observing first of all the nature of the relation of the intellect to universal being. For we find an intellect whose relation to universal being is that of the act of all being; and such is the Divine intellect, which is the Essence of God, in which originally and virtually, all being pre-exists as in its first cause. And therefore the Divine intellect is not in potentiality, but is pure act.
Intellectus enim, sicut supra dictum est, habet operationem circa ens in universali. Considerari ergo potest utrum intellectus sit in actu vel potentia, ex hoc quod consideratur quomodo intellectus se habeat ad ens universale. Invenitur enim aliquis intellectus qui ad ens universale se habet sicut actus totius entis; et talis est intellectus divinus, qui est Dei essentia, in qua originaliter et virtualiter totum ens praeexistit sicut in prima causa. Et ideo intellectus divinus non est in potentia, sed est actus purus.
But no created intellect can be an act in relation to the whole of universal being; otherwise it would needs be an infinite being. Wherefore every created intellect is not the act of all things intelligible (by reason of its very existence as created) but is compared to these intelligible things as a potentiality to act.
Nullus autem intellectus creatus potest se habere ut actus respectu totius entis universalis; quia sic oporteret quod esset ens infinitum. Unde omnis intellectus creatus (per hoc ipsum quod est) non est actus omnium intelligibilium, sed comparatur ad ipsa intelligibilia sicut potentia ad actum.
Now, potentiality has a double relation to act. There is a potentiality which is always perfected by its act, as with the matter of the heavenly bodies (Q58, A1). And there is another potentiality which is not always in act, but proceeds from potentiality to act; as we observe in things that are corrupted and generated.
Potentia autem dupliciter se habet ad actum. Est enim quaedam potentia quae semper est perfecta per actum, sicut diximus de materia corporum caelestium. Quaedam autem potentia est, quae non semper est in actu, sed de potentia procedit in actum; sicut invenitur in generabilibus et corruptibilibus.
Wherefore the angelic intellect is always in act as regards those things which it can understand, by reason of its proximity to the first intellect, which is pure act, as we have said above.
Intellectus igitur angelicus semper est in actu suorum intelligibilium, propter propinquitatem ad primum intellectum, qui est actus purus, ut supra dictum est.
But the human intellect, which is the lowest in the order of intelligence and most remote from the perfection of the Divine intellect, is in potentiality with regard to things intelligible, and is at first "like a clean tablet on which nothing is written", as the Philosopher says (De Anima iii, 4). This is made clear from the fact, that at first we are only in potentiality to understand, and afterwards we are made to understand actually.
Intellectus autem humanus, qui est infimus in ordine intellectuum, et maxime remotus a perfectione divini intellectus, est in potentia respectu intelligibilium, et in principio est "sicut tabula rasa in qua nihil est scriptum", ut philosophus dicit in III de anima. Quod manifeste apparet ex hoc, quod in principio sumus intelligentes solum in potentia, postmodum autem efficimur intelligentes in actu.
The Philosopher says (De Anima iii, 4) that "to understand is in a way to be passive." To be passive may be taken in three ways.
Philosophus dicit, in III de anima, quod "intelligere est pati quoddam". Pati tripliciter dicitur.
Firstly, in its most strict sense, when from a thing is taken something which belongs to it by virtue either of its nature, or of its proper inclination; as when water loses coolness by heating, and as when a man becomes ill or sad.
Uno modo, propriissime, scilicet quando aliquid removetur ab eo quod convenit sibi secundum naturam, aut secundum propriam inclinationem; sicut cum aqua frigiditatem amittit per calefactionem, et cum homo aegrotat aut tristatur.
Secondly, less strictly, a thing is said to be passive, when something, whether suitable or unsuitable, is taken away from it. And in this way not only he who is ill is said to be passive, but also he who is healed; not only he that is sad, but also he that is joyful; or whatever way he be altered or moved.
Secundo modo, minus proprie dicitur aliquis pati ex eo quod aliquid ab ipso abiicitur, sive sit ei conveniens, sive non conveniens. Et secundum hoc dicitur pati non solum qui aegrotat, sed etiam qui sanatur; non solum qui tristatur, sed etiam qui laetatur; vel quocumque modo aliquis alteretur vel moveatur.
Thirdly, in a wide sense a thing is said to be passive, from the very fact that what is in potentiality to something receives that to which it was in potentiality, without being deprived of anything.
Tertio modo, dicitur aliquid pati communiter, ex hoc solo quod id quod est in potentia ad aliquid, recipit illud ad quod erat in potentia, absque hoc quod aliquid abiiciatur.
"Passive intellect" is the name given by some to the sensitive appetite, in which are the passions of the soul; which appetite is also called "rational by participation," because it "obeys the reason" (Ethic. i, 13). Others give the name of "passive intellect" to the cogitative power, which is called the "particular reason." And in each case "passive" may be taken in the two first senses, inasmuch as this so-called "intellect" is the act of a corporeal organ.
"Intellectus passivus" secundum quosdam dicitur appetitus sensitivus, in quo sunt animae passiones; qui etiam in I Ethic. dicitur "rationalis per participationem", quia "obedit rationi". Secundum alios autem "intellectus passivus" dicitur virtus cogitativa, quae nominatur "ratio particularis". Et utroque modo "passivum" accipi potest secundum primos duos modos passionis, inquantum talis "intellectus" sic dictus, est actus alicuius organi corporalis.
But the intellect which is in potentiality to things intelligible, and which for this reason Aristotle calls the "possible" intellect (De Anima iii, 4) is not passive except in the third sense, because it is not an act of a corporeal organ. Hence it is incorruptible.
Sed intellectus qui est in potentia ad intelligibilia, quem Aristoteles ob hoc nominat intellectum "possibilem", non est passivus nisi tertio modo, quia non est actus organi corporalis. Et ideo est incorruptibilis.