116 Irenaeus: Life, Scripture, LegacyConclusion
Irenaeus clearly sets out his self-declared purpose for writing his five-volume work in
the preface to volume one. He states his assessment that “certain men have set the truth
aside,” and in response he outlines his agenda. Believing that “error, indeed, is never
set forth in its naked deformity, lest, being thus exposed, it should at once be detected,”
he sets out to write an exposé of such errors in order that “men may no longer be
drawn away by the plausible system of these heretics.” This task was not undertaken in
ignorance. There is no doubt that Irenaeus knew much concerning the belief systems
of his opponents. Whether what he knew totally corresponded to what he wrote may
be debated, and at the very least it must be acknowledged that Irenaeus wrote in such
a manner so as to portray his opponents’ beliefs in an unfavorable light. His work was
no neutral assessment, rather it is written with the passion of a polemicist—albeit a
rather well-informed one.
This brief survey has tried to assess which written “gospel-like” sources Irenaeus
may have known. He shows clear knowledge of the four canonical Gospels, which he
sees as the basis of knowledge of the truth. As was described, he is the earliest extant
source that explicitly acknowledges the fourfold gospel canon, although (perhaps
ironically, at least for Irenaeus), implicitly Tatian’s Diatesseron may witness the fourfold
canon maybe a decade earlier.^34 The focus of the discussion has been, however, not
on the sources that Irenaeus affirms as being free from error, but on those texts from
which he may have gained knowledge of the belief systems that he seeks to refute. Two
gospel-type sources are explicitly named, the Gospel of Judas and the Gospel of Truth. In
terms of genre, one can sympathize with the reasons why Irenaeus saw these as being
so different from the four texts he accepted as being “gospels.” The Gospel of Judas is a
revelatory discourse, in which the Saviour reveals the mysteries of the Sethian under-
standing of the cosmos. The similarities between the recently discovered Gospel of Judas
and Irenaeus’s description of a text with the same name suggests that a Greek version of
the same text that has come down to modern readers was known to Irenaeus.
On the other hand, it was more difficult to conclude with certainty anything con-
cerning Irenaeus’s knowledge of the Gospel of Truth. Whereas he knew of a text bearing
that title, modern readers know only of a text that speaks of the “gospel of truth,” in its
opening line, as a source of joy to those who apprehend it. However, these words are
not written either as a titular prescript or superscript. Nonetheless, such evidence was
seen as suggestive of the hypothesis that Irenaeus knew a form of the same text that
was discovered at Nag Hammadi. Yet, because there are no direct citations from this
text, and because Irenaeus appears to conjoin elements that might have been found
in this text with more advanced descriptions of Valentinian cosmology, it cannot be
determined whether he gained information concerning the beliefs of Valentinus and
his followers directly from the text, or whether he objected to this sermon-like tractate,
because it circulated widely to attract potential adherents to the movement.
The Alpha-Beta logion was known to Irenaeus in a form that was closest to its
second, shorter version contained in the Greek A recension of the Infancy Gospel of
Thomas. That multiple forms were incorporated into the same text strongly suggests
that this pericope had a prehistory before it was integrated into the Infancy Gospel