[66] And if any persons do attend, they sit all that time only listening, and when they have departed they do not recollect a word of what has been said, but they have come in fact rather to be pleased through the medium of their hearing than with the view of deriving any solid advantage; [19] [20] so that their soul has not been able to comprehend anything or to become pregnant with any new idea, and even the cause which at first excited their pleasure soon ceases and their attention is extinguished.