At the Councils of Arles and Nicaea, calendar diversity was conceived, for the
first time in history, as a social evil; the cohesion of Christian society was linked,
for thefirst time, to the observance of Easter by all Christians on the same date.
This led, again for thefirst time, to the identification of calendar deviance as
‘heresy’, and to the rise of separatist Christian groups that were defined as
‘heretical’ purely because of their calendar observances—so much so that
calendar differences could be exploited, as we have just seen, as a means of
breaking away from orthodoxy and constructing innovative, heretical identities.
In the fourth century, calendar difference became socially significant: it meant
social separation, excommunication, and schism. This paradigm has become
entrenched inWestern culture until the present day, and has led, for example, to
modern scholarly construals of calendar diversity in ancient Judaism as the
cause of the Qumran community’s sectarian schism.
The ideas put forward at Arles and Nicaea, however, were not completely
innovative. The notion of a‘correct’calendar, indeed, had already existed in
early Judaism (e.g. in the book of Jubilees and in early rabbinic sources) and
early Christianity (as evident from the controversy ofc.190CE). However, the
polemical discourses that were formed in this context were about correct
practice and authority, not about the universal observance, by all people, of
the same calendar. Simultaneous observance of festivals by all communities
was not a realistic objective, nor was it really sought after; in a world where
communications were still slow and unreliable, calendar diversity within early
Judaism and Christianity could often go unnoticed and was not regarded as an
issue.
Nevertheless, it may be argued more generally that the pursuit of orthodoxy
and universality or‘catholicism’, which were closely related to the enforce-
ment of a single Easter date in the fourth century, had earlier roots in Christian
tradition. Already in the third century, Anatolius justified his Easter cycle as
‘catholic’because it incorporated a wide range of calendrical traditions, which
suggests, perhaps, that he was aiming at a certain ideal of calendar unity. The
development offixed Easter cycles in the course of the third century may also
itself have contributed to the rising notion of calendar orthodoxy and unity,
even if the invention of these cycles was initially generated by entirely different
motives: for pseudo-Cyprian (in 243CE), for example, to reckon the Christian
Easter independently from the Jewish Passover, and for Anatolius and the
Alexandrian computists, to establish the authentic, post-equinoctial dates of
the Biblical Easter.^181 The invention offixed Easter cycles—to whatever extent
they were used in practice in the third century—opened the way for the
standardization of the Christian calendar. These cycles made it possible for
(^181) See above, near nn. 76, 84. At the end of Ch. 6, I have also interpreted the institution of
fixed Easter cycles that were tied to the Julian or Alexandrian calendars as a way of‘normalizing’
Christian lunar calendars within Roman imperial society.
Sectarianism andHeresy 423