Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that one angel does not know another. For the Philosopher says (De Anima iii, text. 4), that if the human intellect were to have in itself any one of the sensible things, then such a nature existing within it would prevent it from apprehending external things; as likewise, if the pupil of the eye were colored with some particular color, it could not see every color. But as the human intellect is disposed for understanding corporeal things, so is the angelic mind for understanding immaterial things. Therefore, since the angelic intellect has within itself some one determinate nature from the number of such natures, it would seem that it cannot understand other natures.

Objection 2: Further, it is stated in De Causis that "every intelligence knows what is above it, in so far as it is caused by it; and what is beneath it, in so far as it is its cause." But one angel is not the cause of another. Therefore one angel does not know another.

Objection 3: Further, one angel cannot be known to another angel by the essence of the one knowing; because all knowledge is effected by way of a likeness. But the essence of the angel knowing is not like the essence of the angel known, except generically; as is clear from what has been said before (Question 50, Article 4; Question 55, Article 1, ad 3). Hence, it follows that one angel would not have a particular knowledge of another, but only a general knowledge. In like manner it cannot be said that one angel knows another by the essence of the angel known; because that whereby the intellect understands is something within the intellect; whereas the Trinity alone can penetrate the mind. Again, it cannot be said that one angel knows the other by a species; because that species would not differ from the angel understood, since each is immaterial. Therefore in no way does it appear that one angel can understand another.

Objection 4: Further, if one angel did understand another, this would be either by an innate species; and so it would follow that, if God were now to create another angel, such an angel could not be known by the existing angels; or else he would have to be known by a species drawn from things; and so it would follow that the higher angels could not know the lower, from whom they receive nothing. Therefore in no way does it seem that one angel knows another.

On the contrary, We read in De Causis that "every intelligence knows the things which are not corrupted."

I answer that, As Augustine says (Gen. ad lit. lit. ii), such things as pre-existed from eternity in the Word of God, came forth from Him in two ways: first, into the angelic mind; and secondly, so as to subsist in their own natures. They proceeded into the angelic mind in such a way, that God impressed upon the angelic mind the images of the things which He produced in their own natural being. Now in the Word of God from eternity there existed not only the forms of corporeal things, but likewise the forms of all spiritual creatures. So in every one of these spiritual creatures, the forms of all things, both corporeal and spiritual, were impressed by the Word of God; yet so that in every angel there was impressed the form of his own species according to both its natural and its intelligible condition, so that he should subsist in the nature of his species, and understand himself by it; while the forms of other spiritual and corporeal natures were impressed in him only according to their intelligible natures, so that by such impressed species he might know corporeal and spiritual creatures.

Reply to Objection 1: The spiritual natures of the angels are distinguished from one another in a certain order, as was already observed (Question 50, Article 4, ad 1,2). So the nature of an angel does not hinder him from knowing the other angelic natures, since both the higher and lower bear affinity to his nature, the only difference being according to their various degrees of perfection.

Reply to Objection 2: The nature of cause and effect does not lead one angel to know another, except on account of likeness, so far as cause and effect are alike. Therefore if likeness without causality be admitted in the angels, this will suffice for one to know another.

Reply to Objection 3: One angel knows another by the species of such angel existing in his intellect, which differs from the angel whose image it is, not according to material and immaterial nature, but according to natural and intentional existence. The angel is himself a subsisting form in his natural being; but his species in the intellect of another angel is not so, for there it possesses only an intelligible existence. As the form of color on the wall has a natural existence; but, in the deferent medium, it has only intentional existence.

Reply to Objection 4: God made every creature proportionate to the universe which He determined to make. Therefore had God resolved to make more angels or more natures of things, He would have impressed more intelligible species in the angelic minds; as a builder who, if he had intended to build a larger house, would have made larger foundations. Hence, for God to add a new creature to the universe, means that He would add a new intelligible species to an angel.

Articulus 2

Argumentum 1

Ad secundum sic proceditur. Videtur quod unus Angelus alium non cognoscat.

Dicit enim philosophus, in III de anima, quod si intellectus humanus haberet in se aliquam naturam de numero naturarum rerum sensibilium, illa natura interius existens prohiberet apparere extranea, sicut etiam si pupilla esset colorata aliquo colore, non posset videre omnem colorem.

Sed sicut se habet intellectus humanus ad cognoscendas res corporeas, ita se habet intellectus angelicus ad cognoscendas res immateriales. Cum igitur intellectus angelicus habeat in se aliquam naturam determinatam de numero illarum naturarum, videtur quod alias cognoscere non possit.

Argumentum 2

Praeterea, in libro de causis dicitur quod omnis intelligentia sit quod est supra se, inquantum est causata ab eo; et quod est sub se, inquantum est causa eius.

Sed unus Angelus non est causa alterius.

Ergo unus Angelus non cognoscit alium.

Argumentum 3

Praeterea, unus Angelus non potest cognoscere alium per essentiam ipsius Angeli cognoscentis, cum omnis cognitio sit secundum rationem similitudinis, essentia autem Angeli cognoscentis non est similis essentiae Angeli cogniti nisi in genere, ut ex supra dictis patet; unde sequeretur quod unus Angelus non haberet de alio cognitionem propriam, sed generalem tantum.

Similiter etiam non potest dici quod unus Angelus cognoscat alium per essentiam Angeli cogniti, quia illud quo intellectus intelligit, est intrinsecum intellectui; sola autem trinitas illabitur menti. Similiter etiam dici non potest quod unus cognoscat alium per speciem, quia illa species non differret ab Angelo intellecto, cum utrumque sit immateriale. Nullo igitur modo videtur quod unus Angelus possit intelligere alium.

Argumentum 4

Praeterea, si unus Angelus intelligit alium, aut hoc esset per speciem innatam, et sic sequeretur quod, si deus nunc de novo crearet aliquem Angelum, quod non posset cognosci ab his qui nunc sunt. Aut per speciem acquisitam a rebus, et sic sequeretur quod Angeli superiores non possent cognoscere inferiores, a quibus nihil accipiunt.

Nullo igitur modo videtur quod unus Angelus alium cognoscat.

Sed Contra

Sed contra est quod dicitur in libro de causis, quod omnis intelligentia scit res quae non corrumpuntur.

Corpus

Respondeo dicendum quod, sicut Augustinus dicit, II super Gen. Ad litt., ea quae in verbo dei ab aeterno praeextiterunt, dupliciter ab eo effluxerunt, uno modo, in intellectum angelicum; alio modo, ut subsisterent in propriis naturis. In intellectum autem angelicum processerunt per hoc, quod deus menti angelicae impressit rerum similitudines, quas in esse naturali produxit. In verbo autem dei ab aeterno extiterunt non solum rationes rerum corporalium, sed etiam rationes omnium spiritualium creaturarum. Sic igitur unicuique spiritualium creaturarum a verbo dei impressae sunt omnes rationes rerum omnium, tam corporalium quam spiritualium.

Ita tamen quod unicuique Angelo impressa est ratio suae speciei secundum esse naturale et intelligibile simul, ita scilicet quod in natura suae speciei subsisteret, et per eam se intelligeret, aliarum vero naturarum, tam spiritualium quam corporalium, rationes sunt ei impressae secundum esse intelligibile tantum, ut videlicet per huiusmodi species impressas, tam creaturas corporales quam spirituales cognosceret.

Ad 1

Ad primum ergo dicendum quod naturae spirituales Angelorum ab invicem distinguuntur ordine quodam, sicut supra dictum est.

Et sic natura unius Angeli non prohibet intellectum ipsius a cognoscendis aliis naturis Angelorum, cum tam superiores quam inferiores habeant affinitatem cum natura eius, differentia existente tantum secundum diversos gradus perfectionis.

Ad 2

Ad secundum dicendum quod ratio causae et causati non facit ad hoc quod unus Angelus alium cognoscat, nisi ratione similitudinis, inquantum causa et causatum sunt similia. Et ideo, si inter Angelos ponatur similitudo absque causalitate, remanebit in uno cognitio alterius.

Ad 3

Ad tertium dicendum quod unus Angelus cognoscit alium per speciem eius in intellectu suo existentem, quae differt ab Angelo cuius similitudo est, non secundum esse materiale et immateriale, sed secundum esse naturale et intentionale. Nam ipse Angelus est forma subsistens in esse naturali, non autem species eius quae est in intellectu alterius Angeli, sed habet ibi esse intelligibile tantum. Sicut etiam et forma coloris in pariete habet esse naturale, in medio autem deferente habet esse intentionale tantum.

Ad 4

Ad quartum dicendum quod deus unamquamque creaturam fecit proportionatam universo quod facere disposuit. Et ideo, si deus instituisset facere plures Angelos vel plures naturas rerum, plures species intelligibiles mentibus angelicis impressisset.

Sicut si aedificator voluisset facere maiorem domum, fecisset maius fundamentum. Unde eiusdem rationis est quod deus adderet aliquam creaturam universo, et aliquam speciem intelligibilem Angelo.