Easter in world Christianity on the same day. They seem to be responding only
to local controversies and conflicts of authority within the city of Rome where,
since the days of Blastus, the date of Easter had become a significant political
issue. In this respect, the implicit designation, in these heresiologies, of the
observance of the 14th as‘heretical’might be rather specific, in the context of
early third-century Christianity, to the Christian community in Rome.
The attribution of the Refutatioto Hippolytus is significant, however,
because seemingly the same Hippolytus is attributed the earliest known
computation of the date of Easter, a 112-year cycle that began in 222CE
(already examined in Chapter 6, near nn. 90, 98).^76 This was the beginning
of a gradual process in the Christian world, through the third and fourth
centuries, whereby the date of Easter became increasingly determined through
computus orfixed, calculated schemes. The motivations for designing and
adopting these schemes were complex and varied. By the fourth century, as we
shall later see, Easter cycles came to play a critical role in the unification of
Christian communities, the eradication of calendar diversity, and the standar-
dization of orthodox calendars. But in Hippolytus’period, Easter cycles may
have been motivated by other, more specific agendas, not least the polemic
against observance of Easter on the 14th.
Hippolytus’cycle, indeed, was designed in such a way as to provide not only
the dates ofluna XIV(the 14th of the moon), but also the dates of Easter
Sunday (see Ch. 6 n. 90). The lunar dates were based on a double octaeteris or
eight-year cycle, thus 16 years, but this period had to be multiplied by seven
(thus 167 = 112), the number of days in the week, in order to ensure that at
the end of the cycle Easter Sunday would return to the same date as at the
beginning. The construction of this lengthy (and as it happens, not particularly
accurate) cycle was thus governed by one paramount objective: to facilitate, on
a permanent basis, the observance of Easter on Sunday. This objective was
directly related to theRefutatio’s opposition to observance of Easter onluna
XIV.
Another probable motivation behind the introduction of Easter cycles in
this period was the complex relationship between Judaism and Christianity,
and the ongoing Christian quest for a distinct identity. As we have seen,
observance of Easter on the 14th was interpreted by pseudo-Tertullian as a
Judaizing practice—because this is when the Jews observed Passover—and the
same is implicit in theRefutatio’s interpretation of the practice as conforming
to the Law of Moses. However, the dependence of the Christian Easter on the
Jewish Passover affected Sunday observers as much as observers of the 14th.
Before the introduction of Easter cycles, indeed, the date of Easter for most
Christians, whether on the 14th or on the following Sunday, would have been
(^76) On the question of whether it actually is the same‘Hippolytus’or the same author, see
above, n. 72.
388 Calendars in Antiquity