J. Quasten writes (Patrology, vol. 1, pp. 256-260):

The work of Basilides was continued by his son and pupil Isidore, of whom we know even less than of his father. Clement of Alexandria (Stromat. 2,113; 6,53; 3,1-3) has a few quotations from three of his writings. He wrote An Explanation of the Prophet Parchor, in which he tried to prove that the Greek philosophers borrowed from the prophets. In addition he composed an Ethica and a treatise On the Attached Soul. The latter deals with the human passions, which emanate from a second part of the soul. The passage which Clement quotes from the Ethica gives an odd interpretation of the Lord’s words on the eunuch (Matt. 19,10ff.).
Isidore is therefore a minor figure in second century Gnosticism.
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