It is said that the ordeal through which the candidates were obliged to pass previous to admission into the Egyptian mysteries, were even more severe, and that Pythagoras, wise philosopher as he was, had a narrow escape from it. The priests alone could arrive at a thorough understanding of the mysteries. So sacred were their secrets held that many of the members of the sacerdotal order, even, were not admitted to a participation of them; but those alone who proved themselves deserving of the honor; since Clement of Alexandria, tells us: "the Egyptians neither entrusted their mysteries to every one, nor degraded the secrets of divine matters by disclosing them to the profane, reserving them for the heir apparent to the throne, and for such of the priests as excelled in virtue and wisdom." From all we can learn on the subject, the mysteries consisted of two kinds, the greater and the lesser, divided into many classes. The candidate for initiation had to be pure, his character without blemish. He was commanded to study such lessons as tended to purify the mind. Great was the honor of ascending to the greater mysteries and it was difficult to attain to it. An inscription of a high priest at Memphis, says Mr. Samuel Birch, states: "That he knew the arrangements of the Earth, and those of Heliopolis and Memphis; that he had penetrated the mysteries of every sanctuary; that nothing was concealed from him; that he adored God and glorified Him in all His works, and that he hid in his breast all that he had seen." Had he not kept his secrets so carefully concealed, no doubt he would have told us that at one of the initiations the figure of the god Osiris, in whose honor the mysteries were celebrated, and whose name the initiates did not dare pronounce, appeared to the candidate, as it did at Heliopolis to Pianchi, king of Ethiopia. At a later period, when the ancient customs had become relaxed owing to the invasion of the country by foreigners and to the government passing from the hands of native rulers to those of Persian, of Greek or Roman governors, many, besides the priests, came to be admitted to the lesser mysteries. But all had to pass through the different grades and conform to the prescribed rules, as in the case of Thales, Eumolpus, Orpheus, Pythagoras, Plato, Herodotus and others.