Tertullian — On the Soul 16
This too belongs to the faith: Plato divides the soul two ways, through the rational and the irrational. We applaud that definition as well — but not so that both are charged to nature. The rational is to be believed natural: it was inborn in the soul from the beginning, from a rational Author. What is not rational that God has also brought forth by command — still less what he sent out by his own breath? The irrational is to be understood later: it happened from the serpent's prompting — that very admitting of the transgression — and from then rooted and grew in the soul already after the likeness of something natural, because it happened at once in nature's beginning.
But when the same Plato says only the rational is natural, as in the soul of God himself, if we also ascribe the irrational to the nature our soul received from God, then the irrational will equally be from God as natural, because God is nature's author. Yet the injecting of the offense is from the devil; every offense is irrational; so the irrational is from the devil, from whom also the offense — foreign to God, from whom the irrational is alien. See also this whole triad in the Lord: the rational, by which he teaches and lays the ways of salvation; the indignant, by which he inveighs against scribes and Pharisees; and the desiring, by which he desires to eat the Passover with his disciples. So with us indignation and desire are not always to be counted from the irrational — we are sure they ran rationally in the Lord. God will be angry rationally at those who deserve it, and will desire rationally what is worthy of himself.
Latin
[1] Est et illud ad fidem pertinens, quod Plato bifariam partitur animam, per rationale et inrationale. Cui definitioni et nos quidem applaudimus, sed non ut naturae deputetur utrumque. Naturale enim rationale credendum est, quod animae a primordio sit ingenitum, a rationali uidelicet auctore. Quid enim non rationale, quod deus iussu quoque ediderit, nedum id quod proprie afflatu suo emiserit? Inrationale autem posterius intellegendum est, ut quod acciderit ex serpentis instinctu, ipsum illud transgressionis admissum, atque exinde inoleuerit et coadoleuerit in anima ad instar iam naturalitatis, quia statim in naturae primordio accidit. [2] Ceterum cum idem Plato <naturale> solum rationale dicat, ut in anima dei ipsius, si nos etiam inrationale naturae adscribimus, quam a deo anima nostra sortita est, aeque inrationale de deo erit, utpote naturale, quia naturae deus auctor est. Sed enim a diabolo immissio delicti, inrationale autem omne delictum; igitur a diabolo inrationale, a quo et delictum, extraneum a deo, a quo est inrationale alienum. Proinde delicti diuersitas horum ex distantia auctorum. [3] Proinde cum Plato soli deo segregans rationale duo genera subdiuidit ex inrationali, indignatiuum, quod appellant θυμικόν , et concupiscentiuum, quod uocant ἐπιθυμητικόν , ut illud quidem commune sit nobis et leonibus, istud uero cum muscis, rationale porro cum deo, uideo et de hoc mihi esse retractandum propter ea quae in Christo deprehenduntur.
[4] Ecce enim tota haec trinitas et in domino: et rationale, quo docet, quo disserit, quo salutis uias sternit, et indignatiuum, quo inuehitur in scribas et Pharisaeos, et concupiscentiuum, quo pascha cum discipulis suis edere concupiscit. [5] Igitur apud nos non semper ex inrationali censenda sunt indignatiuum et concupiscentiuum, quae certi sumus in domino rationaliter decucurrisse. Indignabitur deus rationaliter, quibus scilicet debet, et concupiscet deus rationaliter, quae digna sunt ipso. Nam et malo indignabitur et bono concupiscet salutem. [6] Dat et apostolus nobis concupiscentiam: si quis episcopatum concupiscit, bonum opus concupiscit; et bonum opus dicens rationalem concupiscentiam ostendit. Concedit et indignationem. Quidni, quam et ipse suscepit? Vtinam et praecidantur, inquit, qui uos subuertunt. Rationalis et indignatio quae ex affectu disciplinae est. [7] At cum dicit: fuimus aliquando natura filii irae, inrationale indignatiuum suggillat, quod non sit ex ea natura quae a deo est, sed ex illa quam diabolus induxit, dominus et ipse dictus sui ordinis: non potestis duobus dominis seruire, pater et ipse cognominatus: uos ex diabolo patre estis, ne timeas et illi proprietatem naturae alterius adscribere, posterioris et adulterae, quem legis auenarum superseminatorem et frumentariae segetis nocturnum interpolatorem.