Mark 9:38-41

I thought priests were the only ones who could cast out demons. John tells Jesus that the one who did it “was not one of us”.

Any thoughts?

Historically, in the 6th-10th centuries, the minor order of Exorcist was a separate minor order from Acolytes, Lectors, and porters.

From the 1917 Catholic Encyclopedia
The practice of exorcism was not confined to clerics in the early ages, as is clear from Tertullian (Apology 23; cf. On Idolatry 11) and Origen (Against Celsus VII.4). The latter expressly states that even the simplest and rudest of the faithful sometimes cast out demons, by a mere prayer or adjuration (Mark 15:17), and urges the fact as a proof of the power of Christ’s grace, and the inability of demons to resist it. In the Eastern Church, a specially ordained order of exorcists (or of acolytes, or door-keepers) has never been established but in the Western Church, these three minor orders with that of lectors as a fourth) were instituted shortly before the middle of the third century. Pope Cornelius (261-252) mentions in his letter to Fabius that there were then in the Roman Church forty-two acolytes, and fifty-two exorcists, readers, and door-keepers (Eusebius, Church History VI.43), and the institution of these orders, and the organization of their functions, seems to have been the work of Cornelius’s predecessor, Pope Fabian (236-251).

The fourth Council of Carthage (398), in its seventh canon, prescribes the rite of ordination for exorcist; the bishop is to give him the book containing the formulae of exorcism, saying, “Receive, and commit to memory, and possess the power of imposing hands on energumens, whether baptized or catechumens”; and the same rite has been retained, without change, in the Roman Pontifical down to the present day, except that instead of the ancient Book of Exorcisms, the Pontifical, or Missal, is put into the hands of the ordained. From this form it is clear that one of the chief duties of exorcists was to take part in baptismal exorcism. That catechumens were exorcised every day, for some time before baptism, may be inferred from canon of the same council, which prescribed the daily imposition of hands by the exorcists. A further duty is precribed in canon 92, viz: to supply food to, and in a general way to care for, energumens who habitually frequented the Church. There is no mention of pagan energumens, for the obvious reason that the official ministrations of the Church were not intended for them. But even after the institution of this order, exorcism was not forbidden to the laity, much less to the higher clergy, nor did those who exorcised always use the forms contained in the Book of Exorcisms. Thus the Apostolic Constitutions (VIII.26) say expressly that “the exorcist is not ordained”, i.e. for the special office of exorcist, but that if anyone possess the charismatic power, he is to be recognized, and if need be, ordained deacon or subdeacon. This is the practice which has survived in the Eastern Orthodox Church.
newadvent.org/cathen/05711a.htm

For what it’s worth:

At that point in time, the priesthood had not been instituted yet. But in Acts (19:13-16) Jewish exorcists attempting to cast out demons in Christ’s name are rebuked by the demon and then attacked.

Chris

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