Tertullian · a new plain-English translation from the original language
[1] There is also this point, which bears on the faith: that Plato divides the soul in two, into the rational and the irrational. This distinction we too applaud — but not so as to reckon both parts to nature. For the rational must be believed natural, since it was inborn in the soul from the beginning, from its rational Author, of course. For what is not rational, that God has produced even by mere command — let alone what he specifically breathed out from himself? The irrational, on the other hand, must be understood as later: something that came about from the serpent’s prompting — that very commission of the transgression itself — and thereafter took root and grew up together with the soul, to the point that it now looks like a piece of its nature, because it occurred right at the very outset of that nature. [2] But since this same Plato says that only the rational is “natural,” as belonging to the soul of God himself, then if we too assign the irrational to nature — the nature our soul has received from God — the irrational will equally have to be from God, being, as it were, natural, since God is the author of nature. But no: the introduction of sin is from the devil, and every sin is irrational; therefore the irrational is from the devil, from whom sin also comes, a stranger to God, from whom the irrational is likewise a stranger. Accordingly, the sins differ precisely because their authors are so distant from one another. [3] Further, when this same Plato, setting the rational apart for God alone, subdivides the irrational into two kinds — the indignant part, which they call the thumikon, and the desiring part, which they call the epithumetikon — so that the one is shared by us with lions, and the other with flies, while the rational, in turn, is shared with God — I see that I must reconsider this point too, on account of what is found in Christ. [4] For behold, this whole trinity is present even in the Lord: the rational, by which he teaches, by which he reasons, by which he lays out the paths of salvation; the indignant, by which he inveighs against the scribes and Pharisees; and the desiring, by which he desires to eat the Passover with his disciples. [5] Therefore, among us, indignation and desire are not always to be reckoned as belonging to the irrational — since we are certain that in the Lord they ran their course rationally. God will be indignant rationally, at whatever, of course, he ought to be; and God will desire rationally, whatever is worthy of himself. For he will be indignant at evil, and he will desire the salvation of the good. [6] The apostle, too, grants us desire: “If anyone desires the office of bishop, he desires a good work” — and by calling it a good work, he shows this to be rational desire. He allows indignation as well. And why not, since he took it up himself? “Would that they were even cut off,” he says, “who unsettle you.” Rational, too, is that indignation which springs from zeal for discipline. [7] But when he says, “We were once by nature children of wrath,” he is branding the irrational indignant part — as not belonging to that nature which is from God, but to that which the devil introduced, he himself, too, being called lord of his own order: “You cannot serve two masters”; he himself, too, is named father: “You are of your father the devil” — lest you shrink from assigning to him the properties of another, later and adulterated, nature: him whom you read of as the sower of tares over the seed and the nocturnal tamperer with the wheat-bearing crop.