Thus time passed on and the original sense or meaning of these myths, descending slowly by oral tradition, became lost, while the myths themselves were for a long time accepted as historical facts. Nevertheless in all ages there have been men who, like Aristotle, Cicero and Plutarch, have questioned the accuracy of these statements and shown themselves intelligent and active sceptics. During all these times, however, a wily priest-craft had lived and thrived on the superstitions of the common people and the practices in which they have indulged; by these men, thus conditioned, any active doubt was regarded as subversive of the system by which they were supported, and as one not to be tolerated;--this condition pertaining not only to antiquity, since it is too significant a feature even of the early years of this twentieth century. A more or less honest though misinformed priesthood has, in all times, been in favor of the purification of the theology in vogue in their times and among their inner circles, and has in the main given the most rationalistic interpretation to the obscure things which they taught, and practised what their education and environment would permit. But in order to preserve the mysteries, to maintain them as such, and save themselves from becoming superfluous, not to say intolerable, these same mysteries have been tricked out with mysticism, symbolism of the most fantastic character, and allegory of the most bewildering kind; moreover this has often been accomplished by dramatic representations and by moralizing or demoralizing ceremonies. The countries in which these "mysteries," as they have since been known, were most commonly practised and most widely believed were Egypt, Chaldea and Greece. The sources of the Egyptian mysteries, like those of Egyptian civilization, are the most difficult to discover. The Nile is necessarily the basis of Egyptian history, geography, activity and habits, and consequently must be also of the Egyptian cult. The people who were known as Egyptians invaded the land of the Nile from the direction of Asia, and found there a race of negro type whom they subdued and with whom they later mingled. The Semites called the land Misraim; the Greeks finally changed the name of its great river to Neilos. The country is a land of enigmas. Who built those pyramids, and why? Who originated the system of pictorial writing which we call the hieroglyphic? Who planned those wonderful temples now either in ruins, as in upper Egypt, or buried beneath the desert sands, as in lower Egypt? Who brought and erected those mighty blocks of stone or massive slabs from enormous distances, and handled them as we could scarcely do to-day with the best of modern machinery?