Thomas de Vio, O.P., Cardinal Cajetan (1469-1534) was one of the most important commentators on the Summa theologiæ of St. Thomas, whose teachings he defended against Scotists, Renaissance Humanists, and Protestant Reformers. In the following passage he explicates St. Thomas’s use of the traditional likeness of the subjection of temporal to spiritual power to the subjection of the body to the soul. Translated by Timothy Wilson.
St. Thomas, ST IIaIIæ, q. 60, a. 6, obj. 3 and ad 3:
Obj. 3: Moreover, spiritual power is distinguished from temporal power. But sometimes prelates having spiritual power involve themselves in those matters which pertain to the secular power. Therefore usurped judgment is not unlawful.
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Ad 3: To the third, it should be said that the secular power is subject to the spiritual power as the body to the soul. And thus judgment is not usurped if a spiritual prelate involves himself in temporal matters so far as concerns those matters in which the secular power is subject to the spiritual, or which are granted to the spiritual power by the secular power.
Commentary of Cardinal Cajetan, in IIamIIæ, q. 60, a. 6
Having omitted the fifth article, the matter of which (as regards subjects) has been discussed in the preceding Book; in the sixth article, in the response to the third objection, note that the Author, assuming from the decretal Solitæ benignitatis, de Maiorit. et Obed. that the temporal power is subject to the spiritual as the body to the soul, assigns two modes in which the spiritual power involves itself in temporal things: the first of which belongs to the spiritual power from its nature; while the second belongs to it from another, namely, from the secular power itself.
Now, for evidence of this assumption, know, from the De anima bk. II [415b8-12; St. Th., In libros de anima, lib. II, lect. vii], that the soul acts upon the body according to three kinds of cause: namely, effectively, because it effects the corporeal motions of the animal; formally, because it is its form; and finally, because the body is for the sake of the soul. And it is similar, proportionally speaking, regarding the spiritual power in respect of the secular power: indeed, it is as its form and mover and end. For it is manifest, that the spiritual is formal in respect of the corporeal: and by this, the power administering of spiritual things is formal in respect of the power administering of secular things, which are corporeal. It is also indubitably clear, that corporeal and temporal things are for the sake of spiritual and eternal things, and are ordered to these as an end. And since a higher end corresponds to a higher agent, moving and directing; the consequence is, that the spiritual power, which is concerned with spiritual things as its first object, moves, acts, and directs the secular power and those things which belong to it to the spiritual end. And from this it is clear that the spiritual power, of its very nature, commands the secular power to the spiritual end: for these are the things in which the secular power is subject to the spiritual. The text intends this specification with the words: so far as concerns those matters in which the secular power is subject to the spiritual. The Author observes by this, that the secular power is not wholly subject to the spiritual power. On account of this, in civil matters one ought rather to obey the governor of the city, and in military matters the general of the army, than the bishop, who should not concern himself with these things except in their order to spiritual things, just as with other temporal matters. But if it should happen that something of these temporal things occurs to the detriment of spiritual salvation, the prelate, administering of these things through prohibitions or precepts for the sake of spiritual salvation, does not move the sickle unto another’s crop, but makes use of his own authority: for as regards these things, all secular powers are subject to the spiritual power. And thus, besides the thing assumed, the first mode by which the spiritual power judges of temporal things is clear.
And the second mode, namely, from the concession of the secular power, is quite sufficiently clear in prelates who have both jurisdictions in many places, as gifts from princes.