Lives and Opinions of Eminent Philosophers

​Having therefore written all the rest, we fulfill what you requested, these reflections being likely to be useful to many others as well, and especially to those who have recently tasted genuine inquiry into nature and those entangled in deeper preoccupations with ordinary education. Comprehend them thoroughly, therefore, and holding them in memory, run through them swiftly together with the rest that we sent in the short epitome to Herodotus. "First of all, then, do not believe that there is any other end to be obtained from the knowledge of celestial phenomena—whether treated in connection with other topics or independently—than tranquility and firm conviction, just as is the case with the rest of our studies.

​Do not force what is impossible, nor maintain in every respect a mode of inquiry identical either with the discourses concerning ways of life or with the solutions of the other physical problems, such as that the universe is bodies and intangible nature, or that the elements are indivisible bodies, and all such matters as have a unique correspondence with the phenomena. This unique correspondence does not hold in the case of celestial phenomena; rather, these possess both a multiple cause of their coming into being and a predicate of their essence that accords with the senses.

"For we must not study nature in accordance with empty axioms and arbitrary legislation, but as the phenomena demand. For our life has no need now of unreason and empty opinion, but of our living without disturbance. All things, therefore, take place unshakably, and all matters are explained in a multiple manner in accordance with the phenomena, whenever one duly leaves room for what is plausibly said concerning them; but whenever one accepts one explanation and rejects another that is equally in accordance with the phenomenon, it is evident that he falls completely outside of natural science and slips into myth. Moreover, one must bring forward as signs for the occurrences accomplished in the heavens certain phenomena observed among us, which are seen in the way they exist, and not the celestial phenomena themselves; for the latter admit of coming to be in multiple ways.

​Nevertheless, the appearance of each phenomenon must be preserved, and one must distinguish the elements connected with it, which are not testified against by what happens among us as being accomplished in multiple ways. "A world is a circumscribed section of heaven, encompassing heavenly bodies and earth and all visible phenomena, having a severance from the infinite and terminating [and ending at a limit either rare or dense, at the dissolution of which all things within it will undergo confusion] either in a boundary revolving or in one maintaining rest, and having a circular, triangular, or any kind of contour whatsoever. For it is possible in every way; for none of the phenomena bears contrary witness in this world, in which its termination cannot be grasped.

"That such worlds are also infinite in number can be comprehended, and that such a world can come into being both within a world and in an interworld—by which we mean the space between worlds—in a place containing much void, and not in a vast pure void, as some say. This occurs when certain suitable seeds have flowed from a single world or interworld, or from several, gradually effecting additions, articulations, and transpositions to another place, if it so happens, and irrigations from things appropriately disposed, until completion and permanence are achieved, for as long as the underlying foundations are able to sustain the reception.

​For there must not merely be an accumulation, nor a vortex in the void in which it is possible for a world to arise, growing by necessity according to the accepted opinion until it collides with another, as someone among the so-called natural philosophers says; for this is in conflict with the phenomena. "The sun, the moon, and the other heavenly bodies did not come into being independently and were only afterward enclosed by the world [along with whatever else it preserves]; rather, they were molded and received their growth from the beginning [and likewise earth and sea] through the accretions and rotations of certain fine-particled entities, either airy or fiery or both; for perception suggests these things to us in this way."