Vitae philosophorum

For in the study of nature we must not conform to empty assumptions and arbitrary laws, but follow the promptings of the facts; for our life has no need now of unreason and false opinion; our one need is untroubled existence. All things go on uninterruptedly, if all be explained by the method of

However, we must observe each fact as presented, and further separate from it all the facts presented along with it, the occurrence of which from various causes is not contradicted by facts within our experience.

A world is a circumscribed portion of the universe, which contains stars and earth and all other visible things, cut off from the infinite, and terminating [and terminating in a boundary which may be either thick or thin, a boundary whose dissolution will bring about the wreck of all within it] in an exterior which may either revolve or be at rest, and be round or triangular or of any other shape whatever. All these alternatives are possible: they are contradicted by none of the facts in this world, in which an extremity can nowhere be discerned.

That there is an infinite number of such worlds can be perceived, and that such a world may arise in a world or in one of the intermundia (by which term we mean the spaces between worlds) in a tolerably empty space and not, as some maintain, in a vast

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[*](Democritus; cf. Hippol. p. 565, 13 D φθείρεσθαι δὲ τοὺς κόσμους ὑπʼ ἀλλήλων προσπίπτοντας; Atius ii. 4. 9.) 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][*](This must be a gloss, because earth and sea are made of less subtle atoms than the heavenly bodies.) by the accretions and 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.[*](Cf. Lucr. v. 564-591; Philodemus Περὶ σημείων 10. 35 —11. 8; Cic. Acad. Pr. 82, 123; De Fin. i. 20.) [This he states in the eleventh book On Nature. 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 which the brightness begins to diminish.] But in itself and actually it may be a little larger or a little smaller, or

And the rising and setting of the sun, moon, and stars may be due to kindling and quenching,[*](The opinion of Heraclitus (p. 32 B, 6 D) and Xenophanes, and Metrodorus of Chios. Servius, however (ad Verg. G. i. 249, Aen. iv. 584), attributes the theory to the Epicureans.) 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[*](Cf. Lucr. v. 509 f.) 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 ...