CHAPTER XI.
PTOLEMAEUS AND HERACLEON--CELSUS--THE MURATORIAN FRAGMENT.
We are now very near emerging into open daylight; but there are three items in the evidence which lie upon the border of the debateable ground, and as questions have been raised about these it may be well for us to discuss them.
We have already had occasion to speak of the two Gnostics Ptolemaeus and Heracleon.

It is necessary, in the first place, to define the date of their evidence with greater precision, and, in the second, to consider its bearing.
Let us then, in attempting to do this, dismiss all secondary and precarious matter; such as (1) the argument drawn by Tischendorf [Endnote 254:1] from the order in which the names of the disciples of Valentinus are mentioned and from an impossible statement of Epiphanius which seems to make Heracleon older than Cerdon, and (2) the argument that we find in Volkmar and 'Supernatural Religion' [Endnote 254:2] from the use of the present tense by Hippolytus, as if the two writers, Ptolemaeus and Heracleon, were contemporaries of his own in 225-235 A.D.Hippolytus does indeed say, speaking of a division in the school of Valentinus, 'Those who are of Italy, of whom is Heracleon and Ptolemaeus, say' &c.
But there is no reason why there should not be a kind of historic present, just as we might say, 'The Atomists, of whom are Leucippus and Democritus, hold' &c., or 'St.Peter says this, St.
Paul says that.' The account of such presents would seem to be that the writer speaks as if quoting from a book that he has actually before him.

It is not impossible that Heracleon and Ptolemaeus may have been still living at the time when Hippolytus wrote, but this cannot be inferred simply from the tense of the verb.

Surer data are supplied by Irenaeus.
Irenaeus mentions Ptolemaeus several times in his first and second books, and on one occasion he couples with his the name of Heracleon.

But to what date does this evidence of Irenaeus refer?
At what time was Irenaeus himself writing.