The following are the contents of the eighth book of the Refutation of all Heresies:—

What are the opinions of the Docetæ, and that they have formed the doctrines which they assert from natural philosophy.

How Monoïmus ^[904] trifles, devoting his attention to poets, and geometricians, and arithmeticians.

How (the system of) Tatian has arisen from the opinions of Valentinus and Marcion, and how this heretic (from this source) has formed his own doctrines. Hermogenes, however, availed himself of the tenets of Socrates, not those of Christ.

How those err who contend for keeping Easter on the fourteenth day.

What the error is of the Phrygians, who suppose that Montanus, and Priscilla, and Maximilla, are prophets.

What the conceit is of the Encratites, and that their opinions have been formed not from the Holy Scriptures, ^[905] but from themselves, and the Gymnosophists among the Indians.