Lastly, supposing the luminous atmosphere of our sun to have been of such a character as to concentrate itself wholly around the centre of the system, and that as it became concentrated it acquired its intense luminosity, we have in both the production of light from the same cause; and in both it would follow that the concentration of this matter within the orbit of the earth would effect the separation of day from night, by illuminating alternately the opposite sides of the earth. It is true that the theory of La Place does not provide for any such special condensation of luminous matter, nor for any precise stage of the process as that in which the arrangements of light and darkness should be completed; but under his hypothesis it seems necessary to account in some such way for the sole luminosity of the sun; and the point of separation of day and night must have been a marked epoch in the history of the process for each planet. The theory of accretion of matter which has in modern times been associated with that of La Place would equally well accord with the indications in our Mosaic record.[45] It is further to be observed that so long as the material of the earth constituted a part of the great vaporous mass, it would be encompassed with its diffused light, and that after it had been left outside the contracting solar envelope, it might still retain some independent luminosity in its atmosphere, a trace of which may still exist in the auroral displays of the upper strata of the air. The earth might thus at first be in total darkness. It might then be dimly lighted by the surrounding nebulosity, or by a luminous envelope in its own atmosphere. Then it might, as before explained, relapse into the darkness of its misty mantle, and as this cleared away and the light of the sun increased and became condensed, the latter would gradually be installed into his office as the sole orb of day. It is quite evident that we thus have a sufficient hypothetical explanation of the light of the first of the creative aeons; and this is all that in the present state of science we can expect. "Where is the way where light dwelleth? and as for darkness, where is the place thereof, that thou shouldest take it to the bound thereof, and know the way to the house thereof?"