It is well indeed to know all. But the man whose soul is destitute of the ability to reach to acquaintance with many subjects of study, will select the principal and better subjects alone. For real science (ἐπιστήμη, which we affirm the Gnostic alone possesses) is a sure comprehension (κατάληψις), leading up through true and sure reasons to the knowledge (γνῶσις) of the cause. And he, who is acquainted with what is true respecting any one subject, becomes of course acquainted with what is false respecting it.