Again, a two-fold nature of things may be surveyed, the one indeed according to progression, which always makes things that have a secondary arrangement subordinate to those that are prior to them; but the other according to conversion, which conjoins extremes to primary natures through similitude, and produces one circle of the whole generation. Since also the world is spherical, but a figure of this kind is the peculiarity of things that subsist according to conversion, earth likewise must be conjoined in it to the heavens, through one. circle, and one similitude. For thus also the centre is most similar to the poles. For the heavens indeed entirely comprehend wholes, being moved about the poles; but the earth is allotted permanency in the centre. For it is appropriate to generation that the immoveable should be more ancient than that which is moved. Hence, according to all these conceptions it may be said, that earth as co-ordinate with heaven, is the most ancient of the Gods within the heavens. For she is within them, as being on all sides comprehended by them. For as the demiurgus fashioned the whole of a corporeal nature within the soul of the world, thus also he fabricated earth within the heavens, as compressed and contained by them, and in conjunction with them fabricating wholes. She has, however, so far as she is _the first_ of the Gods, an indication of transcendency according to essence; but so far as she is _the most ancient_, she exhibits to our view the dignity which she is allotted. For how is it possible not to admit that she is allotted a great portion in the world, and is very honourable, in whom there are the tower of Jupiter, and the progression of Saturn? For not only Tartarus, which is the extremity of the earth, is on all sides comprehended by Saturn, and the Saturnian power, but also whatever else may be conceived subordinate to this. For Homer says that this is connectedly contained through the sub-tartarean Gods. Not that he arranges Gods beyond Tartarus, as the words indicate; but that Tartarus itself is on all sides comprehended by them.