Numerous facts combine to show us that the philosophical wisdom of the Greeks rested on the same mental basis as mystical knowledge. We only understand the great philosophers when we approach them with feelings gained through study of the Mysteries. With what veneration does Plato speak of the "secret doctrines" in the _Phaedo_. "And it almost seems," says he, "as though those who have appointed the initiations for us are not at all ordinary people, but that for a long time they have been enjoining upon us that any one who reaches Hades without being initiated and sanctified falls into the mire; but that he who is purified and consecrated when he arrives, dwells with the gods. For those who have to do with initiations say that there are many thyrsus-bearers, but few really inspired. These latter are, in my opinion, none other than those who have devoted themselves in the right way to wisdom. I myself have not missed the opportunity of becoming one of these, as far as I was able, but have striven after it in every way." It is only a man who is putting his own search for wisdom entirely at the disposal of the condition of soul created by initiation who could thus speak of the Mysteries. And there is no doubt that a flood of light is poured on the words of the great Greek philosophers, when we illustrate them from the Mysteries. The relation of Heraclitus of Ephesus (535-475 B.C.) to the Mysteries is plainly given us in a saying about him, to the effect that his thoughts "were an impassable road," and that any one, entering upon them without being initiated, found only "dimness and darkness," but that, on the other hand, they were "brighter than the sun" for any one introduced to them by a Mystic. And when it is said of his book, that he deposited it in the temple of Artemis, this only means that initiates alone could understand him. (Edmund Pfleiderer has already collected the historical evidence for the relation of Heraclitus to the Mysteries. _Cf._ his book _Die Philosophie des Heraklit von Ephesus im Lichte der Mysterienidee_. Berlin, 1886.) Heraclitus was called "The Obscure," because it was only through the Mysteries that light could be thrown on his intuitive views. Heraclitus comes before us as a man who took life with the greatest earnestness. We see plainly from his features, if we know how to reconstruct them, that he bore within him intimate knowledge which he knew that words could only indicate, not express. Out of such a temper of mind arose his celebrated utterance, "All things fleet away," which Plutarch explains thus: "We do not dip twice into the same wave, nor can we touch twice the same mortal being. For through abruptness and speed it disperses and brings together, not in succession but simultaneously."