"How dangerous may often become untrained mediumship, and how thoroughly it was understood and provided against by the ancient sages, is perfectly exemplified in the case of Socrates. The old Grecian philosopher was a "medium"; hence, he had never been initiated into the Mysteries; for such was the rigorous law. But he had his "familiar spirit" as they call it, his daimonium; and this invisible counsellor became the cause of his death. It is generally believed that if he was not initiated into the Mysteries it was because he himself neglected to become so.
But the Secret Records teach us that it was because he could not be admitted to participate in the sacred rites, and precisely, as we state, on account of his mediumship. There was a law against the admission not only of such as were convicted of deliberate witchcraft, but even of those who were known to have "a familiar spirit."
The law was just and logical, because a genuine medium is more or less irresponsible; and the eccentricities of Socrates are thus accounted for in some degree. A medium must be passive; and if a firm believer in his "spirit-guide" he will allow himself to be ruled by the latter, not by the rules of the sanctuary.
A medium of olden times, like the modern "medium" was subject to be entranced at the will and pleasure of the "power" which controlled him; therefore he could not well have been entrusted with the awful secrets of the final initiation, "never to be revealed under the penalty of death." The old sage, in unguarded moments of "spiritual inspiration," revealed that which he had never learned; and was therefore put to death as an atheist." (Chapter X - Modern Phenomena - Ancient & New)