Polycarp was a fundamentalist, and so, it seems, was the Apostle John, as recounted by Irenaeus. This selection is from his Against Heresies, Book III, chapter 3:
There are also those who heard from [Polycarp] that John, the disciple of the Lord, going to bathe at Ephesus, and perceiving Cerinthus within, rushed out of the bath-house without bathing, exclaiming, "Let us fly, lest even the bath-house fall down, because Cerinthus, the enemy of the truth, is within." And Polycarp himself replied to Marcion, who met him on one occasion, and said, "Dost thou know me? ""I do know thee, the first-born of Satan." Such was the horror which the apostles and their disciples had against holding even verbal communication with any corrupters of the truth; as Paul also says, "A man that is an heretic, after the first and second admonition, reject; knowing that he that is such is subverted, and sinneth, being condemned of himself."