precisely as great as it is seen to be. For so too fires of which we have experience are seen by sense when we see them at a distance. And every objection brought against this part of the theory will easily be met by anyone who attends to plain facts, as I show in my work On Suture. And the rising and setting of the sun, moon, and stars may be due to kindling and quenching, provided that the circumstances are such as to produce this result in each of the two regions, east and west : for no fact testifies against this. Or the result might be produced by their coming forward above the earth and again by its intervention to hide them : for no fact testifies against this either. And their motions b may be due to the rotation of the whole heaven, or the heaven may be at rest and they alone rotate according to some necessary impulse to rise, implanted at first when the world was made . . . and this through excessive heat, due to a certain extension of the fire which always encroaches upon that which is near it. c 11 The turnings of the sun and moon in their course may be due to the obliquity of the heaven, whereby it is forced back at these times. 1 * Again, they may equally be due to the contrary pressure of the air or, it may be, to the fact that either the fuel from time to time necessary has been consumed in the vicinity or there is a dearth of it. Or even because such a whirling motion was from the first inherent in these stars so that they move in a sort