This hall is here only through intelligence because, as a hall, its existence would be unknown unless some intelligence built it. This body is not self-luminous; if it were, it would be so in a dead man also. Neither can the mind nor the spiritual body be self-luminous. They are not of the essence of intelligence. That which is self-luminous cannot decay. The luminosity of that which shines through a borrowed light comes and goes; but that which is light itself, what can make that come and go, flourish and decay? We see that the moon waxes and wanes, because it shines through the borrowed light of the sun. If a lump of iron is put into the fire and made red-hot, it glows and shines, but its light will vanish, because it is borrowed. So, decadence is possible only of that light which is borrowed and is not of its own essence.