Chapter I.
On the Origin of the Sacraments.
After having treated of the Trinity of God, the creation of the world, the corruption of sin, the incarnation of the Word, and the grace of the Holy Spirit, now in the sixth place we must treat of sacramental medicine. Concerning which seven things must be considered. For we must treat of the origin, variation, distinction, institution, dispensation, repetition, and integrity of each of the Sacraments.
Concerning the origin of the Sacraments, therefore, this must be held: that the Sacraments are sensible signs, divinely instituted as medicines, in which "under the covering of sensible things the divine power operates more secretly"; so that they "by likeness represent, by institution signify, and by sanctification confer some spiritual grace," by which the soul is healed from the infirmities of vices; and to this they are principally ordained as to their ultimate end. Yet they avail also for humiliation, instruction, and exercise, as for an end that is subordinate to the ultimate end.
Now the reason for understanding the aforesaid is this: because the restorative principle, which is Christ crucified, namely the incarnate Word, who most wisely dispenses all things because He is divine, and most mercifully heals because He is divinely incarnate, must so restore and heal the sick human race in a manner befitting the sick one himself, the sickness, the occasion of falling sick, and the cure of the sickness itself. Now the physician Himself is the incarnate Word, namely the invisible God in a visible nature. The sick man is not only spirit nor only flesh, but spirit in mortal flesh. The disease, moreover, is original sin, which through ignorance infects the mind and through concupiscence infects the flesh. The origin of this sin, although it was principally from the consent of reason, nevertheless took its occasion from the senses of the flesh. In order, therefore, that the medicine might correspond to all the aforesaid, it was necessary that it be not only spiritual, but also have something of sensible signs, so that, just as these sensible things were the occasion of the soul's falling, so they might be the occasion of its rising again. Since, therefore, sensible signs, of themselves, do not have an efficacious ordination to grace, although they have a remote representation by their own nature, hence it was necessary that by the Author of grace they be instituted for signifying and blessed for sanctifying; so that thus they might be by natural likeness representing, by adjoined institution signifying, by superadded blessing sanctifying and preparing for grace, by which our soul may be healed and cured.
Again, since curative grace is not given to the proud, the unbelieving, and the disdainful, it was therefore necessary that these sensible signs be divinely given, which would not only sanctify and confer grace and thereby heal, but also instruct by their signification and humble by their reception and exercise by their diversity; so that thus, through exercise, sloth being excluded from the concupiscible power, through instruction, ignorance being excluded from the rational power, through humiliation, pride being excluded from the irascible power, the whole soul would become curable by the grace of the Holy Spirit, which reforms us according to these three powers unto the image of the Trinity and of Christ.
Finally, since through sensible signs of this kind, divinely instituted, the grace of the Holy Spirit is received and in them is found by those who approach, hence it is that Sacraments of this kind are called vessels and cause of grace—not because grace is substantially contained in them or causally effected by them, since it can only be placed in the soul and can only be infused by God alone—but because in them and through them the grace of healing must be drawn from the supreme physician Christ by divine decree, "although God has not bound His power to the Sacraments."
From the foregoing, therefore, it is apparent not only what the origin of the Sacraments is, but also what their use is, and what their fruit is. For their origin is Christ the Lord; their use, however, is an act that exercises, instructs, and humbles; their fruit, indeed, is the healing and salvation of humanity. — It is also clear what the efficient cause is, namely divine institution; what the material cause is, namely the representation of a sensible sign; what the formal cause is, namely gratuitous sanctification; what the final cause is, namely the medicinal healing of humanity. And because "denomination is taken from the form and from the end," hence it is that they are called Sacraments, as it were sanctifying medicines. For through these the soul is led back from the foulness of vices to perfect sanctification.
And therefore, although they are corporeal and sensible, they are nevertheless to be venerated as holy, because they signify sacred mysteries, they prepare for sacred gifts, they are given by the most holy God, they are divinely consecrated by sacred institution and blessing, and they are established for the most sacred worship of God in the holy Church, so that they rightly ought to be called Sacraments.