I do not know much about him, but I remember reading years back how Tertullian mentions him in his
On the Flesh of Christ (19).
Basically, (from what I can understand) Tertullian asserted that Valentinus (or his followers?) changed John 1:13. So that instead of reading "were" it really should be "was" (in reference to Christ).
Verse 13 is not a continuation of what was said of believers from verse 12, but verse 13 is connected to verse 14 in what was said about Christ.
John 1:13
Who
were born, not of blood nor of the will of the flesh nor of the will of man, but of God. (NASB)
Tertullian says
was
As far as I know there are no Greek manuscripts at all that support Tertullian on this.
I'm not sure if this is anything you are looking for.
The boldface below is mine.
'What then is the meaning of,
Was born not of blood nor of the
will of the flesh nor of the will of a man, but of God?'1 This text will
be of more use to me than to them, when I have refuted those
who falsify it. For they maintain that it was thus written,
Were
born not of blood, nor of the will of the flesh or of a man, but of God,2 as
though it referred to the above-mentioned believers in his name:3<br>and from it they try to prove that there exists that mystic seed of
the elect and spiritual which they baptize for themselves. But
how can it mean this, when those who believe in the name of the
Lord are all of them by the common law of human kind born of
blood and of the will of the flesh and of a man, as also is
Valentinus
himself? Consequently the singular is correct, as referring
to the Lord--
was born . . . of God. Rightly so, because the Word is
God's, and with the Word is God's Spirit, and in the Spirit is
God's power, and God's everything that Christ is. As flesh,
however, he was not born of blood, nor of the will of the flesh
and of a man, because the Word was made flesh by the will of
God: for it is to his flesh, not to the Word, that this denial of a
nativity after our pattern applies; and the reason is that it was
the flesh, not the Word, which might have been expected to be
born that way. 'But in denying, among other things, that he was
born of the will of the flesh, surely it also denies that he was born
of the substance of flesh.' No: because neither does the denial that
he was born of blood involve any repudiation of the substance of
flesh, but of the material of the seed, which material it is agreed is
the heat of the blood, as it were by despumation changed into
a coagulator of the woman's blood. For from the coagulator there
is in cheese a function of that substance, namely milk, which by
chemical action it causes to solidify. We understand, then, a denial
that the Lord's nativity was the result of coition (which is the
meaning of
the will of a man and of the flesh), but no denial that it
was by a partaking of the womb. And why indeed does the
evangelist with such amplification insist that the Lord was born
not of blood nor of the will of the flesh or of a man, except that
his flesh was such as no one would suspect was not born of coition?
Consequently, his denial that it was born of coition involves no
denial that it was born of the flesh, but rather an affirmation that
it was born of the flesh, seeing he does not deny 'of flesh' in the
same terms in which he denies 'of coition'. I put it to you: if the
Spirit of God came down into the womb without the intention of
partaking of flesh from the womb, why did he come down into
the womb? For he might have been made spiritual flesh outside
the womb with far less trouble than within it. To no purpose did
he bring himself into a place from whence he took nothing out.
But it was not to no purpose that he came down into the womb.
Consequently he did receive something from it, because if he did
not receive something from it it was to no purpose that he came
down into it, the more so if he were going to be flesh of such a
character as, being spiritual, had nothing in common with the
womb.
