circles is clear from the disagreements cited by Porphyry over the meaning of animals
represented in the mysteries (De abstinentia4.16). Nevertheless, the miniature cult
images in Danubian style that have been found in German, Judean, and Roman
mithraeasupport the belief that the cult maintained an overall coherence despite
these pressures toward interpretive diversity.
Communication
I have pointed out that Mithraic congregations were relatively exclusive. At Ostia,
it has been reckoned that, allowing a half-meter per man, the 14 now locatable mithraea
might have held on average 35 people: the smallest 18, the largest 40 or 42. Selectivity
of membership was evidently important. There is no question of evangelism, if by
that we mean the lust for indiscriminate conversion projected by the pious literature
of early Christianity. Individual Mithraists must have sought to convince selected
members of their own circle of acquaintances of the merits of Mithras. Pre-existing
groups, slave familiae, the agents of the portoria, the familia Caesaris, and military
units were ideally suited to this sort of “internal conversion,” based upon friendship,
common experience, and shared goals. By the reign of Commodus, for example, the
procurator castrensis, the head of the entire organization of the domestic side of
the imperial palace, was a worshiper of Mithras; at latest by 209–11, probably much
earlier, there was an official Mithraic organization inside the palace (see above).
Although the cleft between life before and life after initiation cannot be com-
pared with that of the claims of Christianity, the moral and psychological demands
led to a sharpened sense of separation from the world of common experience, as
well as the more obvious consciousness of privileged access to a divinity strong to
save (deus praesens: AE1980, 52;praestantissimus: AE1976, 411b; 1991, 1301).
It was this sense of belonging to a moral elite that fueled the process of Mithraic
missionizing.
We may assume that the original nucleus of such congregations was formed by a
very small group of men, perhaps often just a single individual, who had moved to
another town, or slave familia, or military camp, from elsewhere. The basis of such
men’s knowledge of the cult would have been another existing community. In the
absence of explicit evidence we have to use inference. For example, the sole known
Mithraic dedication at Aosta is by a circitor, an itinerant customs inspector, of the
XL Galliarum(AE1989, 334). Again, Firmidius Severinus, a veteran of the vexilla-
tion of VIII Augustaseconded inad 185 to Lugdunum (Lyon), made a dedication
deo invicto genio loci, “to the unconquered God, spirit of this place,” at Geneva in
201 (CIL12.2587). Since he refers to his 26 years of service, but still calls himself
miles, he had probably made the move from Lugdunum fairly recently; the very unusual
title genio locisuggests a mithraeumor cult room here, presumably founded by
Severinus. An analogous process, that of contact-conversion, is clearly implied by the
foundation texts of the first Dura mithraeum(CIMRM38/39; 41, cf. Dirven 1999:
260 –72): Ethpeni, the commander of the numerus Palmyrenorumlong stationed in
Dura, who dedicated the first cult relief there inad 168, must have been stimulated
400 Richard Gordon