In his commentary on the seven holy orders, Honorius prefers to trace each order to a precedent in the Old Law, so that the hierarchy of the Church is a sort of mirror of the Temple ministry instituted by David and Solomon.
But the orders are also bound up with the distinctively Roman culture of the Latin Church, as we can see in the following extracts from Margaret Deanesly, A History of the Medieval Church, page 28:
“In the time of Gregory I the conception of the clergy as the ‘clerical militia’ was already long developed. The imperial civil service had provided a ladder of offices, by which a candidate, beginning at the bottom, might proceed through the ‘cursus honorum’ to the highest civil or military rank. The parallel between this ladder and the various grades of the Christian minister had not been unnoticed by Christian bishops, and by 600 the commonest collective description of the clergy was the ‘clerical militia,’ or the ‘celestial’ in opposition to the ‘secular’ militia. The celestial militia consisted of seven orders, its sevenfold nature denoting the perfection of the divine service: ostiarius, lector, acolyte, subdeacon, deacon, presbyter, or sacerdos [….]
About the year 600 the first three minor orders were usually conferred together; boys were ordained lectors at about seven years of age, and received the other grades at intervals of several years, till they were ordained to the presbyterate at the age of forty-five [….]
This was due to the system of education in the bishop’s familia. After the destruction of the rhetorical schools in the barbarian invasions, the bishop’s house became the only place where the clergy might reasonably hope for an education [….]
Gregory of Tours relates how, at the death of a Gallic bishop, the bishops summoned for his funeral encountered a claim from one Cato, a presbyter of his clergy, to be ordained bishop almost as of right, from his due canonical reception of the various grades. ‘For,’ he said, ‘I have been allotted these grades of clerkship with canonical institution. I was a lector ten years, I ministered in the office of subdeacon for five years, fifteen years was I bound for the diaconate, and now for twenty years I have enjoyed the honour of the presbyterate. What now remains for me but to receive…the episcopate?'”