Summa de Ecclesia

If one rightly weighs what we said above explaining who are to be called in the state of perfection and who not, he will easily understand that there is truly a difference between bishop and priest. But since we have shown bishops to be in the state of perfection, and priests, even with cure, as not, we consequently prove the difference to be real between bishop and priest. That this real difference also existed always from the institution of these dignities is easy for us to prove. That about the times of Jerome and Augustine the distinction was so is clear from the testimony of blessed Augustine, who in his letter to Jerome, as found in ch. Quartum, ii, q. vii, says: Although, according to the titles of honor which the usage of the Church has now obtained, the episcopate is greater than the presbyterate, yet in many things Augustine is less than Jerome. Second, that such difference existed in the time of the apostles or of the primitive Church is clear from the fact that Dionysius, who lived in their time, writing the book on the Ecclesiastical Hierarchy, in ch. 5 thereof treats of three orders of the hierarchy, namely of bishops, priests, and deacons, saying the order of deacons is of those who purify, the order of priests of those who illuminate, and the order of bishops of those who perfect. To these three orders, as he himself says in the following ch. 6, three orders correspond. For to the order of deacons is subjected the order of the impure, who need purification; to the order of priests is subjected the order of those to be illuminated, namely the holy people, who are illuminated by priests through reception of the sacraments; to the order of bishops is subjected the order of the perfect, namely the monks, who through their teaching traditions are led to most perfect perfection. Third, that this difference was instituted not by human invention but by divine disposition from Christ appears from Matt. 10, where it is said: The Lord designated, etc., where the Gloss says: As in the apostles is the form of bishops, so in the 72 disciples is the form of priests of the second order, where it is expressly held that the difference between bishops and priests of the second order was instituted by Christ. Fourth, the aforesaid difference is shown from the fact that it is read as prefigured in the Old Testament, as blessed Isidore puts it, found in ch. Clerus, dist. 21, where it is said that the high priests and the lesser were instituted by God through Moses, who by the Lord's command appointed Aaron as high priest, and his sons as lesser priests. And thus it is clear that really, from the beginning of the institution of these orders in the Church, there was always a real difference between bishop and priest. Hence blessed Aug. in the book on heresies enumerates among heretical doctrines the saying that priests do not differ from bishops, saying that the Arians said a priest ought to be discerned from a bishop by no difference, as St Thomas says in II-II, q. 184, arg. 6. Nor does what Jerome says on the Apostle to Timothy stand against the foregoing, saying: Once priest was the same as bishop. And afterwards he adds: As priests, therefore, by the custom of the Church are subject to him who is set over them as bishop, so let bishops know that they are greater than priests more by custom than by the truth of the Lord's dispensation. Concerning this it must be noted that of bishop and priest we speak in two ways. In one way as to the name, and thus once bishops and priests were not distinguished. For bishops are so called as overseers, as Augustine says in City of God 19, while priests are called in Greek as elders. Hence the Apostle commonly uses the name of priests for both, when he says in 1 Tim. 5: Let priests who rule well be held worthy of double honor. And likewise the name of bishops, whence he says in Acts 20: Take heed to yourselves and to all the flock in which the Holy Spirit has placed you bishops to rule the Church of God. Second, they are considered as to the reality, and thus, as we have already shown by many reasons above, there was always a distinction between them. Hence Isidore says, found in dist. 21, ch. Clerus, that lesser priests, although priests, nevertheless have not the crown of the pontificate, since they neither seal the forehead with chrism nor give the Paraclete Spirit, which belongs to bishops alone, as the Acts show. Hence also among the ancients, although there was agreement in the name and promiscuous use of terms, for there can be another reason, that not only were terms promiscuous, but episcopate and presbyterate were also in one person, since bishops also exercised the simple presbyteral office on account of the scarcity both of pastors and of flock, yet there was difference in reality. Afterwards, however, to avoid the error of schism arising from indifference of names, it was necessary that the names also be distinguished, namely that only the greater priests be called bishops, and the lesser only priests, as St Thomas says.