Basics of Epicurean Physics

1. Nature: There Are No Supernatural Gods; The Universe Operates on Natural Principles Which Derive from The Properties And Combinations Of the Atoms

The claims in this outline are not offered as scientific hypotheses that a single new observation could simply overturn. They are logical arguments grounded in the unbroken and universal testimony of human experience – no one has ever observed something arise from absolute nothing, or anything vanish into absolute nothing, in the whole of recorded history – and modern physics, so far from threatening these conclusions, has generally confirmed rather than undermined them.

1. Nothing comes from nothing and nothing goes to nothing.
1. Therefore the universe as a whole has existed eternally.
2. Therefore the universe was not created at any single point in time, neither by a god nor by any other single event.
3. Epicurus:

   “…nothing comes into being out of what is not. For in that case everything would come into being out of everything, with no need for seeds. Also, if that which disappears were destroyed into what is not, all things would have perished, for lack of that into which they dissolved. Moreover, the totality of things was always such as it is now, and always will be, since there is nothing into which it changes, and since beside the totality there is nothing which could pass into it and produce the change.”

   Letter to Herodotus 38–9
2. Ancient and modern thinkers have argued that the order visible in the universe requires an intelligent, purposive cause standing behind it – a designer. This argument has a long history: Anaxagoras proposed that a cosmic Mind (Nous) set the universe in order; Plato's Timaeus describes a divine craftsman, the Demiurge, who fashioned the world using the eternal Forms as a pattern; Aristotle argued for an eternal, all-perfect Unmoved Mover toward which everything in nature strives as its final purpose; and the Stoics built an entire theology around Providence (a Greek term meaning "forethought") – the doctrine that a divine, rational fire pervades and directs the universe for the benefit of its inhabitants. Epicurus rejected every version of this argument, on several independent grounds at once. Cicero has the Epicurean spokesman Velleius state the rejection in exactly these terms:

   “Listen to no ungrounded and fictitious doctrines: no creator and builder of the world like the god from Plato's Timaeus; no prophetic hag like the Stoics' Providence, no world which is itself an animate, sentient, spherical, glowing, rotating god. These prodigies and marvels are the work of philosophers who dream, not argue.”

   On the Nature of the Gods 1:18-23
1. Therefore, on logical and evidentiary grounds: no designing mind has ever been observed, and no observation could distinguish a designed universe from an undesigned one. The argument infers an unobserved cause from an observed effect without any way of confirming that inference. And positing an eternal, self-existing intelligence to explain the universe's order explains nothing, since that same eternal, self-existing status could simply be granted to the universe itself, without the unexplained addition of a designer standing behind it. Lucretius states the same point directly:

   “And not by design did the primary bodies of things station themselves each in their right place, guided by keen intelligence, nor indeed did they make contracts about the movements each was to perform; but because many primary bodies of things in many ways, struck with blows and carried along by their own weight from infinite time up to the present, have been accustomed to move and meet in every way and to try everything that they could produce by coming together...”

   De Rerum Natura, Book 2
2. Therefore, on physical grounds: the actual condition of the world is not what a benevolent design would produce. Most of the earth is uninhabitable – buried in mountains, forest, desert, or sea; disease and hostile conditions are everywhere; and the one creature capable of reason is born more helpless and dependent than almost any other animal. Lucretius makes the point concretely rather than abstractly:

   “...why does nature sustain and multiply on land and sea the dreadful hordes of wild beasts? Why do the seasons bring diseases with them? Why is untimely death rife? A child, when nature has first spilt him forth with throes from his mother's womb into the realm of light, lies like a sailor cast ashore from the cruel waves – naked on the ground, without speech, helpless for life's tasks...”

   De Rerum Natura, Book 5
   The imperfection of the world is exactly what an undirected natural process, not intelligent design, would be expected to produce.
3. Therefore, on ethical grounds: asserting that a designing intelligence exists is not a harmless speculation but a dangerous one, because it reintroduces precisely the fear, guilt, and submission that a correct understanding of nature is meant to remove. If the universe was made for us by an intelligence with purposes of its own, human beings owe that intelligence obedience, worship, and fear of its judgment – restoring by another route the very anxiety that the recognition below, that any truly perfect being neither causes nor receives trouble, is meant to dispel for good.
3. Everything in the universe is composed of combinations of elementary matter and void.
1. Therefore nothing else exists - no Religious "heaven" or "hell," no Spiritual or other dimension, no Platonic "ideals," no Aristotelian "essences."  Nothing exists except elementary matter, void, and their combinations. Lucretius sets out the exhaustive proof of this directly:

   “...whatever exists in its own right will either act, or must itself be acted on when other things act, or will be such that things are able to exist and happen in it. But nothing can act or be acted on without body, nor provide room except empty void. Therefore, other than void and bodies, no third nature could be left in the tally of things, either to fall under our senses at some time, or to be grasped by anyone through reasoning of the mind.”

   De Rerum Natura I.420-451
4. The combinations formed by elementary matter and void possess real properties that no individual atom possesses on its own – color, temperature, taste, sensation, thought, pleasure and pain, and the capacity to choose.
1. Therefore these properties are not illusions to be explained away as "nothing but" atoms in motion. Epicurus himself insisted, of color specifically, that we must not suppose color is an intrinsic property of atoms, but that it arises from the arrangement, position, and grouping of atoms in a compound – a real property of the compound, even though absent from any atom taken individually:

   “...colour varies according to the disposition of the atoms.”

   Letter to Herodotus 49-50
   Lucretius develops the same point with a vivid image:

   “...if the primary particles are colorless, and possess a variety of shapes from which they generate every kind of thing and thus make colors vary... it at once becomes very easy to explain why things which a little earlier were black in color can suddenly take on the whiteness of marble, as the sea, when its surface has been churned up by great winds, is turned into waves whose whiteness is like that of gleaming marble.”

   De Rerum Natura, Book 2

   The same is true of sensation, thought, and pleasure: none of these belongs to any individual atom, yet all of them genuinely belong to the compounds – including living beings – that atoms form.

2. Therefore the self, the mind, and the will are not something added to the physical world from outside it. They are compounds of atoms and void like everything else, but they are real, causally effective compounds at their own level of organization – not less real for being made of atoms, and not standing apart from matter as some separate, independent kind of thing. The self, as an entity emerging from atoms and void, exercises real influence over its own constituent atoms – which is why deliberation, understanding, and philosophical argument can actually change how a person lives.
5. The amount of elementary matter and void in the universe is unlimited in extent.
1. Therefore the universe as a whole is unlimited in extent.
2. Therefore the universe as a whole has no center and no edge. Lucretius argues this with a simple thought experiment:

   “...suppose that the whole of space were bounded, if someone ran right to its furthest shores and hurled a flying javelin, do you choose to think that that javelin, hurled with great force, would go where it was sent and fly far, or do you think that something could block its path and stop it?... The result will be that the boundary cannot stand anywhere...”

   De Rerum Natura, Book 1
3. Therefore the earth is not uniquely positioned at the center of the universe.
6. The elementary matter is always in motion.
1. Therefore the universe is constantly changing.
7. The elementary matter moves through the void at a uniform speed, but vibrates in compounds due to collisions.
1. Therefore the change in the universe is not chaotic, but subject to laws of motion.
8. The elementary matter is capable of swerving from its path at no fixed place or time.
1. Therefore not everything in the universe is predetermined from the beginning of time.
2. The swerve alone, however, is not sufficient by itself to secure genuine free choice, since an uncaused random deviation in an atom's path is not yet the same thing as a deliberate decision.
3. Therefore what actually makes free choice possible is the combination of the swerve with the fact that a thinking, choosing compound – a living person – is itself a real, causally effective thing in its own right, and not merely another name for the atoms that compose it.
4. Lucretius:

   “If all movement is always one long chain, and new movement arises out of the old in order fixed, and atoms do not swerve and make a start of movement that can break the bonds of fate... then whence comes this free will, this will wrested from the fates, this will by which we move wherever pleasure leads?”

   De Rerum Natura, Book 2
5. Lucretius makes the same point through a concrete image:

   “Don't you see how also when at an instant the starting gates are opened the eager strength of horses can nevertheless not surge forward as suddenly as the mind itself wishes?... Thus you may see that the beginning of motion is created from the heart and proceeds initially from the mind's volition... there is something in our chest capable of fighting and resisting, at whose decision the mass of matter is also forced at times to be turned throughout the limbs and frame...”

   De Rerum Natura, Book 2
6. Diogenes of Oinoanda:

   “If fate is believed in, all admonition and censure are nullified, and not even the wicked can be justly punished, since they are not responsible for their sins.”

   Fragment 54
9. The elementary matter has varying weights, shapes, and sizes, but the number of these variations not infinite, only innumerable.
1. Therefore the properties of elementary matter and the combinations formed by elementary matter and void are not unlimited, but limited by the properties of the elementary matter and its combinations.
10. Combinations of elementary matter and void are not by nature eternal but are created and destroyed.
1. Therefore while the universe as a whole is eternal, the combinations of elementary matter and void are not eternal.
11. To the extent that "perfect" combinations of elementary matter and void exist, such perfect things (including perfect beings) neither cause nor receive trouble, because causing and receiving trouble are characteristics only of things which are weak.
1. Therefore to the extent that any life forms, or any combinations of elementary matter and void, have developed the capacity to live without end, they  neither cause change to us nor or are they changed by any actions we may take.
12. Nature never creates only a single instance of any kind of thing.
1. Therefore life exists throughout the universe, as the Earth cannot possibly be the only place where life exists. Lucretius states the argument directly:

   “Moreover, nothing in the universe is the only one of its kind to be born and to grow, as opposed to belonging to some species, with many members of the same kind. Focus your mind first on animals. You will find that the wild beasts of the mountains, the human race, the speechless swarms of scaly fish, and all flying creatures, have such an origin. Therefore we must likewise admit that heaven, earth, sun, moon, sea, and all other existing things, are not unique but, rather, countless in number.”

   De Rerum Natura, Book 2
13. In the Universe as a whole, every thing has its match and counterpart.  This principle of uniform distribution is known as "isonomia."  Cicero explains the term and its consequence directly:

    “...there is the supremely potent principle of infinity, which claims the closest and most careful study; we must understand that it has the following property, that in the sum of things everything has its exact match and counterpart. This property is termed by Epicurus isonomia, or the principle of uniform distribution. From this principle it follows that if the whole number of mortals be so many, there must exist no less a number of immortals.”

    On the Nature of the Gods 1:XIX
1. Therefore, for example, there are as many "immortal" beings as "mortal" beings in the universe.
2. Therefore, for example, if the causes which bring about destruction of bodies are beyond count, the causes which bring about the coming together of bodies are also beyond count.