Welcome to Episode One Hundred Thirty-Three of Lucretius Today.
This is a podcast dedicated to the poet Lucretius, who wrote "On The Nature of Things," the only complete presentation of Epicurean philosophy left to us from the ancient world.
I am your host Cassius, and together with our panelists from the EpicureanFriends.com forum, we'll walk you through the ancient Epicurean texts, and we'll discuss how Epicurean philosophy can apply to you today. We encourage you to study Epicurus for yourself, and we suggest the best place to start is the book "Epicurus and His Philosophy" by Canadian professor Norman DeWitt.
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Today we complete our discussion of Epicurus' Letter to Pythocles. Now let's join Joshua reading today's text:
Comets occur either when fire is collected together in certain regions at certain intervals of time in the upper air because some gathering of matter takes place, or when at certain intervals the heaven above us has some peculiar movement, so that stars of this nature are revealed, or when they themselves at certain seasons start to move on account of some gathering of matter and come into the regions within our ken and appear visible. And their disappearance occurs owing to the opposite causes to these.
 Some stars ‘revolve in their place’(as Homer says), which comes to pass not only because this part of the world is stationary and round it the rest revolves, as some say, but also because a whirl of air is formed in a ring round it, which prevents their moving about as do the other stars: or else it is because there is not a succession of appropriate fuel for them, but only in this place in which they are seen fixed. And there are many other ways in which this may be brought about, if one is able to infer what is in agreement with phenomena.
 That some of the stars should wander in their course, if indeed it is the case that their movements are such, while others do not move in this manner, may be due to the reason that from the first as they moved in their circles they were so constrained by necessity that some of them move along the same regular orbit, and others along one which is associated with certain irregularities: or it may be that among the regions to which they are carried in some places there are regular tracts of air which urge them on successively in the same direction and provide flame for them regularly, while in other places the tracts are irregular, so that the aberrations which we observe result.
But to assign a single cause for these occurrences, when phenomena demand several explanations, is madness, and is quite wrongly practiced by persons who are partisans of the foolish notions of astrology, by which they give futile explanations of the causes of certain occurrences, and all the time do not by any means free the divine nature from the burden of responsibilities.
 That some stars should be seen to be left behind by others is caused because though they move round in the same orbit they are carried along more slowly, and also because they really move in the opposite direction though they are dragged back by the same revolution: also because some are carried round through a greater space and some through a lesser, though all perform the same revolution. But to give a single explanation of these occurrences is only suitable to those who wish to make a show to the many.
 What are called falling stars may be produced in part by the rubbing of star against star, and by the falling out of the fragments wherever an outburst of wind occurs, as we explained in the case of lightning-flashes: or else by the meeting of atoms productive of fire, when a gathering of kindred material occurs to cause this, and a movement in the direction of the impulse which results from the original meeting; or else by a gathering of wind in certain dense and misty formations, and its ignition as it whirls round, and then its bursting out of what encloses it and its rush towards the spot to which the impulse of its flight tends. And there are other ways in which this result may be brought about, quite free from superstition.
The signs of the weather which are given by certain animals result from mere coincidence of occasion. For the animals do not exert any compulsion for winter to come to an end, nor is there some divine nature which sits and watches the outgoings of these animals and then fulfills the signs they give.
 For not even the lowest animal, although ‘a small thing gives the greater pleasure,’ would be seized by such foolishness, much less one who was possessed of perfect happiness.
All these things, Pythocles, you must bear in mind; for thus you will escape in most things from superstition and will be enabled to understand what is akin to them. And most of all give yourself up to the study of the beginnings and of infinity and of the things akin to them, and also of the criteria of truth and of the feelings, and of the purpose for which we reason out these things. For these points when they are thoroughly studied will most easily enable you to understand the causes of the details. But those who have not thoroughly taken these things to heart could not rightly study them in themselves, nor have they made their own the reason for observing them.
Comets arise either because fire is nourished in certain places at certain intervals in the heavens, if circumstances are favourable; or because at times the heaven has a particular motion above us so that such stars appear; or because the stars themselves are set in motion under certain conditions and come to our neighbourhood and show themselves. And their disappearance is due to the causes which are the opposite of these.
 Certain stars may revolve without setting not only for the reason alleged by some, because this is the part of the world round which, itself unmoved, the rest revolves, but it may also be because a circular eddy of air surrounds this part, which prevents them from travelling out of sight like other stars; or because there is a dearth of necessary fuel farther on, while there is abundance in that part where they are seen to be. Moreover there are several other ways in which this might be brought about, as may be seen by anyone capable of reasoning in accordance with the facts.
 The wanderings of certain stars, if such wandering is their actual motion, and the regular movement of certain other stars, may be accounted for by saying that they originally moved in a circle and were constrained, some of them to be whirled round with the same uniform rotation and others with a whirling motion which varied; but it may also be that according to the diversity of the regions traversed in some places there are uniform tracts of air, forcing them forward in one direction and burning uniformly, in others these tracts present such irregularities as cause the motions observed.
To assign a single cause for these effects when the facts suggest several causes is madness and a strange inconsistency; yet it is done by adherents of rash astronomy, who assign meaningless causes for the stars whenever they persist in saddling the divinity with burdensome tasks.
 That certain stars are seen to be left behind by others may be because they travel more slowly, though they go the same round as the others; or it may be that they are drawn back by the same whirling motion and move in the opposite direction; or again it may be that some travel over a larger and others over a smaller space in making the same revolution. But to lay down as assured a single explanation of these phenomena is worthy of those who seek to dazzle the multitude with marvels.
 Falling stars, as they are called, may in some cases be due to the mutual friction of the stars themselves, in other cases to the expulsion of certain parts when that mixture of fire and air takes place which was mentioned when we were discussing lightning; or it may be due to the meeting of atoms capable of generating fire, which accord so well as to produce this result, and their subsequent motion wherever the impulse which brought them together at first leads them; or it may be that wind collects in certain dense mist-like masses and, since it is imprisoned, ignites and then bursts forth upon whatever is round about it, and is carried to that place to which its motion impels it. And there are other ways in which this can be brought about without recourse to myths.
The fact that the weather is sometimes foretold from the behaviour of certain animals is a mere coincidence in time. For the animals offer no necessary reason why a storm should be produced; and no divine being sits observing when these animals go out and afterwards fulfilling the signs which they have given.
 For such folly as this would not possess the most ordinary being if ever so little enlightened, much less one who enjoys perfect felicity.
All this, Pythocles, you should keep in mind; for then you will escape a long way from myth, and you will be able to view in their connection the instances which are similar to these. But above all give yourself up to the study of first principles and of infinity and of kindred subjects, and further of the standards and of the feelings and of the end for which we choose between them. For to study these subjects together will easily enable you to understand the causes of the particular phenomena. And those who have not fully accepted this, in proportion as they have not done so, will be ill acquainted with these very subjects, nor have they secured the end for which they ought to be studied.