Lives of the Eminent Philosophers

by Pamela Mensch

  77 Furthermore, one must suppose that human nature has received all sorts of lessons from the facts themselves, and has been compelled to learn them, and that reason later refined what it thus received and made additional discoveries, among some peoples more swiftly, among others more slowly, progress being greater at certain seasons and times, at others less. Hence even the names of things were not originally due to convention, but in each of the various tribes, under the influence of particular feelings and particular impressions, men emitted air in a particular way, as determined by each of their feelings and impressions, which varied from region to region. Later on, each tribe imposed its own particular names so that their communications might be less ambiguous and more concise. As for things that are not visible, those who were aware of them introduced them, circulating as names for them the sounds they were moved to utter or which they selected by reasoning, relying on the most readily understood explanation as to why they would express themselves in that way.

  Furthermore, with regard to celestial matters, we must believe that motions, solstices, risings, and settings of celestial bodies, and all such phenomena occur without the direction or command, now or in the future, of a being who at the same time enjoys perfect happiness along with immortality. For troubles, worries, rages, and partialities do not accord with bliss, but arise in weakness, fear, and dependence on neighbors. Nor, in turn, should we hold that swirling masses of fire, while endowed with bliss, undertake these motions at will. Instead, in the case of every term we employ, we must preserve the utter majesty that attaches to such concepts as bliss and immortality, lest we generate views that are out of keeping with that majesty; for such incongruity will engender the gravest mental disturbance. Hence we should attribute this necessity and periodic recurrence to the original entanglements among physical masses that created the world.

  78 79 80 81 82 Furthermore, we must hold that arriving at precise knowledge of the cause of the most important things is the work of natural science, and that our happiness depends on this, and upon understanding what the heavenly bodies actually are, and everything related to them that contributes to the accuracy of our knowledge. Moreover, on such questions we must admit no plurality of causes or alternative explanations, but must simply assume that nothing suggestive of conflict or confusion is compatible with a nature that is immortal and blessed; and the mind is capable of grasping the absolute truth of this. But with regard to subjects for specific inquiry, there is nothing in the knowledge of settings, risings, eclipses, and all related phenomena that contributes to our happiness; on the contrary, those who have obtained some information about these matters and yet remain ignorant about their nature and principal causes feel as much fear as those who have not obtained such information; indeed, their fears might even surpass those of the wholly ignorant, when the dread that results from this additional knowledge prevents them from finding a solution or understanding how these phenomena are regulated in relation to the highest causes. Accordingly, if we discover multiple causes for solstices, risings, settings, eclipses, and the like, as we did in matters of detail, we must not suppose that our treatment of these matters fails to achieve a degree of accuracy sufficient to ensure our undisturbed and happy state. Thus when we investigate the causes of celestial phenomena and everything that is not known, we must take into account the array of ways in which analogous phenomena occur in our experience; and we should disdain those who fail to recognize the difference between what exists or comes to be from a single cause and that which may come about from a variety of causes, because they overlook the fact that the actual objects transmit their impressions from a distance, and are also ignorant of the circumstances under which it is not possible to be free of distress. Hence, if we think that an event might happen in one of several possible ways, then when we discover that it could occur in many different ways we will be as free of distress as if we knew that it occurred in that particular way. In addition to all these considerations, one must grasp one more point, namely that the greatest anxiety for the human mind arises from the belief that these celestial bodies are blessed and indestructible, yet at the same time have volitions, actions, and purposes that conflict with that belief; and from expecting or fearing some everlasting evil, either the kind portrayed in myths, or the actual absence of sensation that attends death, as if it had to do with us; and from the fact that these feelings are due less to our convictions than to a certain irrational propensity. Accordingly, if men do not contain their fear, they suffer an anxiety equal to or greater than that of the man who gives these matters only the occasional random thought. But tranquillity can be attained only by freeing ourselves of all these fears and keeping the principal and most important truths constantly in mind. Hence, we must take note of our present feelings and sensations, whether universal or particular, and pay heed to all the available evidence in light of each of the criteria. For by studying them we shall fully and correctly explain the cause of our anxiety and fear and free ourselves, accounting for celestial phenomena and for all the other regularly occurring phenomena that afflict mankind with its worst fears.

  A Hunting Scene, by Piero di Cosimo, c. 1505–1508.

  Return from the Hunt, by Piero di Cosimo, c. 1505–1508. The principal inspiration for these companion panels showing a hunt by men and satyrs and their return from the hunt was the fifth book of the De Rerum Natura by the Epicurean poet and philosopher Lucretius (c. 99–c. 55 BC).

  83 Here then, Herodotus, you have in summary form the chief points about the nature of all things. Accordingly, if this statement is accurately retained and takes effect, a man will, I presume, be far better prepared than others, even if he does not go into all the exact details. For he will himself elucidate many of the points I have worked out in detail in my complete treatise; and this summary, if retained in memory, will be of constant use to him.

  Its character is such that those who are already adequately, or even perfectly, acquainted with the details can, by distilling their observations into such fundamental concepts as these, best pursue their diligent study of nature as a whole; those, on the other hand, who have not fully mastered the material, will be able to review, silently and with the speed of thought, the doctrines most likely to ensure peace of mind.

  This is his letter on natural science. Next comes his letter on celestial phenomena.

  Epicurus to Pythocles, greetings.

  84 85 Cleon brought me a letter from you in which you continue to express the affection that my zeal on your behalf has earned me, and you try in a convincing manner to recall the arguments that make for a happy life. You also request a concise and well-organized account of the celestial phenomena as an aid to memory; for our other works on the subject are, as you say, hard to remember, though you refer to them constantly. I was glad to receive your request and am full of pleasant expectations. Accordingly, having completed all my other writing, I will grant your request, since these arguments will be useful to many others too, especially to those who have only recently embarked on a genuine study of nature, as well as those who are engaged in pursuits that go deeper than any of the ordinary branches of education. Grasp these doctrines well and, once you have committed them to memory, survey them along with the others in the short epitome I sent to Herodotus.

  86 87 88 First of all, one must bear in mind that, like everything else, knowledge of celestial phenomena, whether studied in connection with other things or in isolation, has no other purpose than to foster tranquillity and firm conviction. We must not try to establish by force what is impossible, nor apply the same method as in our discussions of human lives or the other problems of natural philosophy (where we maintain, for example, that the world consists entirely of bodies and intangible nature, or that the elements are indivisible, or any of the other propositions that admit of only one possible explanation of the phenomena observed). But this is not the case when we come to celestial phenomena, which admit of multiple causes and multiple accounts of their origin an
d nature that are consistent with the evidence of our senses. For the study of nature must be based not on empty rules and arbitrary principles, but on what the phenomena dictate. For our life has no need now for subjective reasoning or empty opinion; instead we need to free our lives of anxiety. Everything proceeds smoothly and in conformity with the phenomena if all is explained in accordance with the method of multiple causes, once we have given due consideration to what is plausibly said about them. But whenever we admit one argument, yet reject another that is equally consistent with the phenomena, it is clear that we abandon the study of nature entirely and plunge into myth. There are certain things in our own experience that furnish evidence of what occurs in the celestial realm, and we see how these occur; but we do not see how celestial phenomena occur, for they may have a variety of possible causes. However, we must preserve each fact as it presents itself, and distinguish from it the attendant facts, the occurrence of which from a variety of causes is not contradicted by our own experience.

  89 90 Invisible Disparities, Anthropic Rock, by Ernesto Klar, 2015. Fused dust and glass, 12.2 × 7.4 × 11.9 cm.

  A world is a circumscribed portion of heaven that contains stars, earth, and all visible things, the dissolution of which will bring about the annihilation of everything within it; it is separated from the unlimited and terminates at a boundary that is either rare or dense; it is either revolving or stationary; it has an outline that is either round or triangular or of any other shape; for every configuration is possible, since none is ruled out by the phenomena of our world, in which no limit is discerned. It can be comprehended that there is an unlimited number of such worlds, and that such a world can come into being in a world or in an interspace (our term for the space between worlds) in a place containing considerable void, but not, as some maintain, in a vast expanse that is completely void.78 A world comes into existence when certain suitable seeds flow from one world or interspace, or from several, and undergo gradual additions, articulations, or migrations, as may chance to occur, and waterings from suitable sources, until they mature and attain a permanence commensurate with the capacity of the foundation previously laid down to sustain them. For more is required than an aggregate or a vortex in the void in which a world may arise (by necessity, as some believe) and grow until it collides with another, as one of the so-called natural scientists says. For this is at odds with the phenomena.

  91 92 93 The sun and moon and the other stars did not come into existence independently, only to be enveloped later into our world and all the parts that preserve it; instead they began to form and grow at the outset [like the earth and sea] by the accretions and rotations of certain fine-grained substances, whether airy or fiery or both; for the evidence of our senses suggests this. The size of the sun and of the other stars relative to us is as great as it appears.79 [This he also says in the eleventh book of his work On Nature; “for if,” he says, “the size of a star had diminished on account of the distance, its brightness would have diminished much more.”] For there is no other distance that could better correspond to this size. But in and of itself it may be slightly larger or smaller or precisely as large as it appears. For that is just how, in our own experience, fires are registered by sense when seen from a distance. And every objection to this part of the theory will easily be dispelled by anyone who pays attention to the evidence, as we demonstrate in our work On Nature. The risings and settings of the sun and moon and other stars may be due to a kindling and an extinguishing, provided that conditions are such, in each of the two regions, as to produce this result; for none of the appearances rules this out. And these risings and settings might be caused by the stars’ appearances above the earth or by occultation;80 for this too is not ruled out by any appearances. And it is not impossible that their motions are caused by the rotation of the entire heaven or by its rest and their rotation according to some compulsion to rise that accompanied the world’s creation. <…> owing to excessive heat caused by the spread of fire, which always travels to adjacent regions. The retrograde motions of the sun and moon may result from an obliquity of the heaven that is periodically imposed; likewise, they may be due to a counterthrust of the air or because the necessary fuel is insufficient or has been exhausted; they may even be due to a whirling motion imparted to these stars from the beginning, which causes them to move in a sort of spiral. For all such explanations and their like are not in conflict with any clear evidence, as long as where details are concerned one adheres to what is possible and can refer each of them to what is consistent with the phenomena, undaunted by the slavish artifices of astronomers.

  94 95 96 The waning and, in turn, the waxing of the moon may be due to the rotation of the body and equally well to configurations assumed by the air; they may also be due to occultations, or may happen in any of the ways the facts of our experience can suggest to explain such phenomena. But one must not be so enamored of the explanation based on a single cause as groundlessly to reject the others from ignorance of what can and cannot be understood by a human being, and the consequent longing to understand what cannot be understood. Furthermore, it may be that the moon’s light emanates from itself; alternatively, it may be derived from the sun. For in our own experience many things are seen to give off their own light, while many derive their light from other things. None of the celestial phenomena stand in the way if one always bears in mind the method of multiple explanations and considers the many consistent hypotheses and causes, instead of paying heed to 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 image of a face in the moon may result from a transposition of its parts or from an occultation, or in any of the other ways that might be seen to accord with the phenomena. With regard to all the celestial phenomena, one must not abandon a method of that kind; for he who fights against the clear evidence will never be able to achieve true peace of mind.

  97 An eclipse of the sun or moon may occur as a result of the extinguishing of their light, as has been seen to occur in our own experience; and by now we know that it may be due to occultation by some other celestial body, either the earth or some other similar body. And thus one must simultaneously review the explanations that are mutually consistent and bear in mind that their simultaneous applicability is by no means impossible. [He says this in the twelfth book of his work On Nature, and adds that the sun is eclipsed when the moon obscures it, and that the moon is eclipsed by the shadow of the earth; alternatively, an eclipse may be due to the moon’s withdrawal. This is also said by Diogenes the Epicurean in the first book of his Selected Writings.]

  Furthermore, we must interpret the regularity of an orbit just as we do various events that regularly occur in our experience. May the nature of the divine not be brought forward to explain this, but let it remain in perfect bliss, relieved of duty. For if this is not done, the entire study of the causes of celestial phenomena will be fruitless, as it has by now proved to be for some who have not adopted a possible method but have fallen into the foolishness of thinking that all these events occur in one way only, and of rejecting all the others that are possible, allowing themselves to be swept away into the realm of the inconceivable, and being unable to take a comprehensive survey of the phenomena that must be taken as signposts.

  98 The variations in lengths of nights and days may be due to the speeding up and slowing down of the sun’s motion in the sky, given the variety of distances it traverses, since it covers some distances more swiftly or more slowly, as is also observed in our own experience; and with these phenomena our own explanations must agree. But those who accept a single explanation find themselves at odds with the phenomena and have failed to consider how a man may acquire knowledge.

  Cypriot limestone inscribed relief, c. third century BC. Zeus, holding a thunderbolt in his right hand, sits on a throne at center. Facing him is Apollo, playing the kithara; the smaller figure behind him is identified as Hermes by the caduceus, his winged herald�
��s staff. Above the gods is a chariot pulled by four winged horses. At the bottom, a long inscription expresses homespun philosophical sentiments about fate and the gods.

  99 The signs indicating weather to be expected may be coincidental, as in the case of the animals we see among us, or they may be due to changes in the air. For neither of these explanations is in conflict with the phenomena; and it is not possible to see in which cases the effect results from one cause or from the other.

  100 Clouds may form and gather either because the air contracts under the pressure of winds, or because atoms that adhere to one another and are suitable to produce this result become enmeshed, or because currents pool together from the earth and the waters; but it is not impossible that the aggregations of such bodies are brought about in several other ways. Rain may be produced when the clouds are either compressed or transformed; or it may be caused by exhalations of winds from appropriate places when there is a more forceful inflow from certain aggregates suitable for such discharges.

  101 102 103 Thunder may be due to the rolling of wind in the hollows of the clouds (as occurs in our cisterns), or to the roaring of fire in them when fanned by a wind, or to their disintegration and dispersal, or to the friction and shattering of frozen clouds. As in our entire inquiry, so in this particular instance, the phenomena require us to entertain multiple explanations. Lightning too occurs in a variety of ways; for when clouds rub against one another and collide, the fire-producing atoms generate lightning. Or lightning may be caused by the wind-blown emission from the clouds of particles likely to produce such brightness, or by the squeezing out of these particles when the clouds are compressed either by one another or by the wind. Alternatively, the light diffused from the stars may be trapped in clouds and then driven through them by their own motions or by the wind. Lightning may also occur when light composed of the finest particles filters through the clouds (at which point the clouds themselves may ignite and produce thunder); or it may occur as a result of the combustion of the wind due to the violence of its motion and the intensity of its compression; or, when the clouds are broken up by winds and the fire-producing atoms are then expelled, these too cause lightning to appear. Lightning may occur in several other ways, as will easily be seen if one adheres to the phenomena and can contemplate what is similar to them. Lightning precedes thunder when the clouds are constituted as described above and the configuration that produces lightning is expelled at the moment when the wind falls upon the cloud; thereafter the pent-up wind produces thunder; or, if both occur at the same time, the lightning travels toward us at a greater speed, the thunder coming later, exactly as when people inflicting blows are observed from a distance.