The Gnostics and Their Remains, by Charles William King, , at sacred-texts.com
That the Pantheus upon our gems was really intended to picture forth the deity styled "Abraxas" can be established by the indirect evidence of many contemporary writers. Irenæus remarks of the Basilidans, that "they use images, incantations, and all other things pertaining unto Magic." Further on (xxiii.) he adds their custom of giving names to their images of pretended angels. And, what bears more directly on the subject, Tertullian (Apol. xvi.), after laughing at the god of the heretics as "biforme numen" (evidently in reference to the serpent legs, "biformes" being the classical synonym for the Giants similarly equipped), then goes on to say, "They have taken unto themselves gods with wings, or with heads of dogs or lions, or else serpents from the legs downwards." Here we have unmistakeable reference to the Magian, Egyptian, and Mithraic idols so common upon these talismans, and in the last words to the serpent-legged and veritable Abraxas-god.
Lastly, Epiphanius, after stating that Basilides had taught that the Supreme Being--out of whom proceeded Mind, Intelligence, Providence, Strength, and Wisdom--was named Abraxas, proceeds to describe in what manner the idea was embodied by
the heresiarch: "Having taken their vain speculations, he and his followers have converted them into a peculiar and definite form, as a foundation for their own erroneous idolatrous and fictitious doctrines." Further on he adds: "With respect to their 'Kavlacav,' what person with any understanding would not laugh at their converting a Hebrew word into a bodily shape in order to represent their idol; at their personified Principalities; in a word, at their fondness for images; whilst through these fancies they sow error in the minds of the ignorant for the furtherance of their disgraceful and lying trade?" Then proceeding, it would appear, to the analysis of the figure itself, he exclaims: "It is a Spirit of deceit, which, like the playing upon a pipe, leads the ignorant into many sins against the Truth. Yea, even his legs are an imitation of the Serpent through whom the Evil One spake and deceived Eve. For after the pattern of that figure hath the flute been invented for the deceiving of mankind. Observe the figure that the player makes in blowing his flute. Both he not bend himself up and down to the right and to the left, like unto it (the serpent)? These forms hath the Devil used to support his blasphemy against heavenly things, to destroy with destruction things upon earth, to encompass the whole world, taking captive right and left all such as lend an ear to his seductions."