Vitae philosophorum

There is yet one more point to seize, namely, that the greatest anxiety of the human mind arises through the belief that the heavenly bodies are blessed and indestructible, and that at the same time they have volitions and actions and causality inconsistent with this belief; and through expecting or apprehending some everlasting evil, either because of the myths, or because we are in dread of the mere insensibility of death, as if it had to do with us; and through being reduced to this state not by conviction but by a certain irrational perversity, so that, if men do not set bounds to their terror, they endure as much or even more intense anxiety than the man whose views on these matters are quite vague.

But mental tranquillity means being released from all these troubles and cherishing a continual remembrance of the highest and most important truths.

Hence we must attend to present feelings and sense perceptions, whether those of mankind in general or those peculiar to the individual, and also attend to all the clear evidence available, as given by each of the standards of truth. For by studying them we shall rightly trace to its cause and banish the source of disturbance and dread, accounting for celestial phenomena and for all other things which from time to time befall us and cause the utmost alarm to the rest of mankind.

Here then, Herodotus, you have the chief doctrines

So that, if this statement be accurately retained and take effect, a man will, I make no doubt, be incomparably better equipped than his fellows, even if he should never go into all the exact details. For he will clear up for himself many of the points which I have worked out in detail in my complete exposition; and the summary itself, if borne in mind, will be of constant service to him.

It is of such a sort that those who are already tolerably, or even perfectly, well acquainted with the details can, by analysis of what they know into such elementary perceptions as these, best prosecute their researches in physical science as a whole; while those, on the other hand, who are not altogether entitled to rank as mature students can in silent fashion and as quick as thought run over the doctrines most important for their peace of mind.

Such is his epistle on Physics. Next comes the epistle on Celestial Phenomena.

Epicurus to Pythocles, greeting.

In your letter to me, of which Cleon was the bearer, you continue to show me affection which I have merited by my devotion to you, and you try, not without success, to recall the considerations which make for a happy life. To aid your memory you ask me for a clear and concise statement respecting celestial phenomena; for what we have written on this subject elsewhere is, you tell me, hard to remember, although you have my books constantly with you. I was glad to receive your request and

We will then complete our writing and grant all you ask. Many others besides you will find these reasonings useful, and especially those who have but recently made acquaintance with the true story of nature and those who are attached to pursuits which go deeper than any part of ordinary education. So you will do well to take and learn them and get them up quickly along with the short epitome in my letter to Herodotus.[*](This would seem decisive of what the Shorter Catechism of Epicurus really was; see, however, § 135.)

In the first place, remember that, like everything else, knowledge of celestial phenomena, whether taken along with other things or in isolation, has no other end in view than peace of mind and firm conviction.[*](Philosophy is defined as an activity which by words and arguments secures the happy life (Sext. Emp. Adv. math. xi.§ 169;cf. Epic. Frag. 222 Us.).)

We do not seek to wrest by force what is impossible, nor to understand all matters equally well, nor make our treatment always as clear as when we discuss human life or explain the principles of physics in general—for instance, that the whole of being consists of bodies and intangible nature, or that the ultimate elements of things are indivisible, or any other proposition which admits only one explanation of the phenomena to be possible. But this is not the case with celestial phenomena: these at any rate admit of manifold causes for their occurrence and manifold accounts, none of them contradictory of sensation, of their nature.

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 ...

and this through excessive heat, due to a certain extension of the fire which always encroaches upon that which is near it.[*](From Lucr. v. 519 f. it is probable that words are lost from the text which ascribed these motions to the quest of fiery atoms by the heavenly bodies.)

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.[*](Cf. Lucr. v. 614 f.) 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

The waning of the moon and again her waxing[*](Cf. Lucr. v. 705-750.) might be due to the rotation of the moon’s body, and equally well to configurations which the air assumes; further, it may be due to the interposition of certain bodies. In short, it may happen in any of the ways in which the facts within our experience suggest such an appearance to be explicable. But one must not be so much in love with the explanation by a single way as wrongly to reject all the others from ignorance of what can, and what cannot, be within human knowledge, and consequent longing to discover the indiscoverable. Further, the moon may possibly shine by her own light, just as possibly she may derive her light from the sun;

for in our own experience we see many things which shine by their own light and many also which shine by borrowed light. And none of the celestial phenomena stand in the way, if only we always keep in mind the method of plural explanation and the several consistent assumptions and causes, instead of dwelling on what is inconsistent and giving it a false importance so as always to fall back in one way or another upon the single explanation. The appearance of the face in the moon may equally well arise from interchange of parts, or from interposition of something, or in any other of the ways which might be seen to accord with the facts.

For in all the celestial phenomena

An eclipse of the sun or moon may be due to the extinction of their light, just as within our own experience this is observed to happen; and again by interposition of something else—whether it be the earth or some other invisible body like it. And thus we must take in conjunction the explanations which agree with one another, and remember that the concurrence of more than one at the same time may not impossibly happen. [He says the same in Book XII. of his De Natura, and further that the sun is eclipsed when the moon throws her shadow over him, and the moon is eclipsed by the shadow of the earth; or again, eclipse may be due to the moon’s withdrawal, and this is cited by Diogenes the Epicurean in the first book of his Epilecta.]

And further, let the regularity of their orbits be explained in the same way as certain ordinary incidents within our own experience; the divine nature must not on any account be adduced to explain this, but must be kept free from the task and in perfect bliss. Unless this be done, the whole study of celestial phenomena will be in vain, as indeed it has proved to be with some who did not lay hold of a possible method, but fell into the folly of supposing that these events happen in one single way only and of rejecting all the others which are possible, suffering themselves to be carried into the realm of the unintelligible, and being unable to take a comprehensive view of the facts which must be taken as clues to the rest.

The variations in the length of nights and days

The signs in the sky which betoken the weather may be due to mere coincidence of the seasons, as is the case with signs from animals seen on earth, or they may be caused by changes and alterations in the air. For neither the one explanation nor the other is in conflict with facts,

and it is not easy to see in which cases the effect is due to one cause or to the other.

Clouds may form and gather either because the air is condensed under the pressure of winds, or because atoms which hold together and are suitable to produce this result become mutually entangled, or because currents collect from the earth and the waters; and there are several other ways in which it is not impossible for the aggregations of such bodies into clouds to be brought about. And that being so, rain may be produced from them sometimes by their compression, sometimes by their transformation;

or again may be caused by exhalations of moisture rising[*](Lucr. vi. 519.) from suitable places through the air, while a more violent inundation is due to certain accumulations suitable for such discharge. Thunder may be due to the rolling of wind in the hollow parts of the clouds, as it is sometimes imprisoned in vessels which we use; or to the roaring of