space perfectly clear and void/' It arises when c ertain suitable sgfids rush in from a single world or intermundium, or from several, and undergo gradual additions or articulations or changes of place, it may 1h\ and watt-rings from appropriate sources, until they are matured and firmly settled in so far as the foundations laid can receive them. For it is not enough that there should be an aggregation or a vortex in the empty space in which a world may arise, as the necessitarians hold, and may grow until it collide with another, as one of the so-called physicists 6 says. For this is in conflict with facts. "The sun and moon and the stars generally were not of independent origin and later absorbed within our world, [such parts of it at least as serve at all for its defence] ; but they at once began to take form and grow [and so too did earth and sea] c by the accretions ancl whirling motions of certain substances of finest texture, of the nature either of wind or fire, or of Both ; for thus sense itself suggests. '* The size of the sun and the remaining stars relatively to us is just as great as it appears/ [This he states in the eleventh book " On Xature." For. says he. if it had diminished in size on account of the distance, it would much more have diminished its brightness ; for indeed there is no distance more proportionate to this diminution of size than is the distance at jvhich the brighbiess begins to diminish.] But in itself and actually it may be a little larger or a little smaller, or b Democritus ; cf. Hippol. p. 565, 13 d <pdeipeadcu 8e rods Koafj-ovs vjt' dWyjXwv wpocnrlirTOPTas ; Aetius ii. 4. 9. c This must be a gloss, because earth and sea are made of less subtle atoms than the heavenly bodies. d Cf. Lucr. v. 564-591 ; Philodemus Ilept <rr]/ieiu)i> 10. 35 —11.8; Cic. Acad. Pr. 82, 1 23; be Ft*, i. 20.