Agrippa Castor has been identified as "the earliest recorded writer against heresy, and apparently the only one who composed a book solely devoted to the refutation of Basilides".
[1] Agrippa Castor was known by both Eusebius and Jerome as an author who provided a critique of Basilides (died c. 132) and his twenty-four books of "Exegetics".
Eusebius mentions him within the narrative of early gnostic "succession" and schools, but provides no other details of his life.
From this time "Agrippa accuses Basilides of teaching that it was a matter of no moral significance to taste food offered to idols", and one could "renounce without reservation the faith in times of persecution" and that "he imposed upon his followers a five years' silence after the manner of Pythagoras".
Agrippa Castor also is recorded as having found in Basilides the same concerns for the numerology, and the use of "Abrasax" for Basilides' "most high God"; the name Abrasax being found engraved on Greek magical gems or recorded in Greek magical papyri.