We shall not enter into those details. We shall not seek to determine the sense which the Egyptians attached, after a certain period, to the word _bâi_,[115] which has been translated _soul_, nor the distinction between it and _khou_, luminousness, which the soul seems to have enveloped like a garment. We shall not follow the soul and its internal light in its subterranean journey across _Ament_, the Egyptian Hades, to which it entered by a cleft, _Pega_, to the west of Abydos, which was the only portal to the kingdom of the shades; nor shall we accompany them in the successive transformations which made them acquainted with every corner of the earth and sky in the infinite series of their _becomes_ (to use the Egyptian expression); what we have to do is to trace out the most ancient of their religious conceptions, the conception which, like the first teachings of infancy, was so deeply engraved upon the soul and intellect of the race as to exercise a much stronger influence than the later more abstract and more philosophical theories, which were superimposed upon it. In this primitive conception we ought to find the determining cause of the Egyptian form of tomb. Its constitution was already settled in the time of the ancient Empire, and, from the Memphite dynasties until the end, it remained unchanged in principle. In this constitution we shall find embodied the essential idea adopted by the Egyptians when they first attempted to find some eternal element in man, or, at least, some element which should resist the annihilation of death for a period much longer than the few days which make up our mortal life. [115] Or _ba_.--ED. The Egyptians called that which does not perish as the dying man draws his last sigh, the _ka_, a term which M. Maspero has rendered as the _double_. "This _double_ was a duplicate of the body in a matter less dense than that of the body, a projection, coloured but aërial, of the individual, reproducing him feature for feature, a child if coming from a child, a woman if from a woman, and a man if from a man."[116]