Thomas Aquinas

“ For by beholding the Word, they know not merely the being of things as existing in the Word, but the being as possessed by the things themselves; as God by contemplating Himself sees that being which things have in their own nature. ”

“ Now the intellect is always true as regards what a thing is, just as the sense regarding its proper object, as is said in De Anima iii, text. 26. But by accident, deception and falsehood creep in, when we understand the essence of a thing by some kind of composition, and this happens either when we take the definition of one thing for another, or when the parts of a definition do not hang together, as if we were to accept as the definition of some creature, "a four-footed flying beast," for there is no such animal. ”

“ In the second way an angel's intellect can be in potentiality with regard to things learnt by natural knowledge; for he is not always actually considering everything that he knows by natural knowledge. But as to the knowledge of the Word, and of the things he beholds in the Word, he is never in this way in potentiality; because he is always actually beholding the Word, and the things he sees in the Word. For the bliss of the angels consists in such vision ”

“ There can be two operations of the same faculty at the one time, one of which is referred to the other; as is evident when the will at the same time wills the end and the means to the end; and the intellect at the same instant perceives principles and conclusions through those principles, when it has already acquired knowledge. ”

“ It would seem that there is neither an evening nor a morning knowledge in the angels; because evening and morning have an admixture of darkness. But there is no darkness in the knowledge of an angel; since there is no error nor falsehood. Therefore the angelic knowledge ought not to be termed morning and evening knowledge. ”

“ Further, nothing is understood unless the intellect be informed by an intelligible species; just at the body is formed by shape. But one body cannot be formed into many shapes. Therefore neither can one intellect simultaneously understand various intelligible things. ”

“ Such is the condition of the angels, because in the truths which they know naturally, they at once behold all things whatsoever that can be known in them.
Therefore they are called "intellectual beings": because even with ourselves the things which are instantly grasped by the mind are said to be understood [intelligi] ; hence "intellect" is defined as the habit of first principles. But human souls which acquire knowledge of truth by the discursive method are called "rational" ”

“ Nor, again, is there any inconsistency in knowing a thing through two mediums, one of which is more perfect and the other less perfect; just as we can have a demonstrative and a probable medium for reaching the same conclusion. In like manner a thing can be known by the angel through the uncreated Word, and through an innate idea. ”

“ Consequently, owing to their upright will, from their knowing the nature of every creature, the good angels form no judgments as to the nature of the qualities therein, save under the Divine ordinance; hence there can be no error or falsehood in them. But since the minds of demons are utterly perverted from the Divine wisdom, they at times form their opinions of things simply according to the natural conditions of the same. ”

“ The morning and evening knowledge belong to the day, that is, to the enlightened angels, who are quite apart from the darkness, that is, from the evil spirits. The good angels, while knowing the creature, do not adhere to it, for that would be to turn to darkness and to night ”

“ But with regard to things divinely revealed to them, there is nothing to hinder them from being in potentiality: because even the heavenly bodies are at times in potentiality to being enlightened by the sun. ”

“ For if they possessed the fulness of intellectual light, like the angels, then in the first aspect of principles they would at once comprehend their whole range, by perceiving whatever could be reasoned out from them. ”

“ But their knowledge of the very being of the thing created, as it stands in its own nature, is termed evening knowledge; because the being of things flows from the Word, as from a kind of primordial principle ”

“ But the angels are always using their morning knowledge; because they are always beholding God and things in God, according to Mat. 18:10. Therefore, if the evening knowledge were different from the morning, the angel could never exercise his evening knowledge. ”

“ Nor are they ever deceived as to the natural properties of anything; but they can be misled with regard to supernatural matters; for example, on seeing a dead man, they may suppose that he will not rise again, or, on beholding Christ, they may judge Him not to be God. ”