[quote="adopted_heir, post:15, topic:269687"]
No, there are not now seven levels in the meaning that there are seven different kinds of priests, but there used to be seven degrees or orders of priesthood (beyond deacon, priest, and bishop's not even counting). There were the Minor Orders, while the priest-to-be was still discerning his vocation. He had minor ordinations and was given specific function at different grades along his formation, and before he reached the Major Orders he was allowed to leave the priesthood. The Minor Orders (which were instituted by the Church and so are not included in the Sacrament of Holy Orders) were: Door-keepers, lectors, exorcists, and acolytes. The Major Orders are: Subdeacons, Deacons, and Priests. Bishops have a separate consecration. This was the case from the beginning of Christendom until within the last century, when the Minor Orders were smashed together under the heading of deacon, or else virtually eliminated (as is the case of exorcists--not many of them now). So, until about fifty years ago, a man could be an exorcist without the fullness of priesthood (Final Orders), and even before he was required to observe celibacy.
I would hesitate to assert, though, that seminarians who reached the minor order of exorcist were actively performing the ministry of exorcism that we're talking about here. Probably at one time in history they did, hence the name, but I'd have to see more documentation to believe that in recent centuries they did.