Among natural philosophers may be enumerated Thales, Pythagoras, Empedocles, Heraclitus, Anaximander, Anaximenes, Anaxagoras, Archelaus, Parmcnides, … - Hippolytus

We note, too, that Hippolytus, who was a Greek-speaking Christian in Rome (c. 225), knows of the Indian Brahmins, and includes their tradition among the sources of heresy: 'There is . . . among the Indians a heresy of those who philosophize among the Brahmins, who live a self-sufficient life, abstaining from (eating) living creatures and all cooked food . . . They say that God is light, not like the light one sees, nor like the sun nor fire, but to them God is discourse, not that which finds expression in articulate sounds, but that of knowledge (gnosis) through which the secret mysteries of nature are perceived by the wise.'

Since, however, reason compels us to plunge into the very depth of narrative, we conceive we should not be silent, but, expounding the tenets of the several schools with minute ness, we shall evince reserve in nothing. Now it seems expedient, even at the expense of a more protracted investigation, not to shrink from labour; for we shall leave behind us no trifling auxiliary to human life against the recurrence of error, when all are made to behold, in an obvious light, the clandestine rites of these men, and the secret orgies which, retaining under their management, they deliver to the initiated only. But none will refute these, save the Holy Spirit bequeathed unto the Church, which the Apostles having in the first instance received, have transmitted to those who have rightly believed.

For the [sorcerer] affirms that it is impossible for mortal nature to behold divine things, for that to hold converse [with these mysteries] is sufficient. Making, however, the attendant lie down [upon the couch], head foremost, and placing by each side two of those little tablets, upon which had been inscribed in, forsooth, Hebrew characters, as it were names of demons, he says that [a demon] will deposit the rest in their ears.