4 ⟨Arius Didymus⟩: Zeno on the center

Of Zeno. In all things within the world that are constituted with their own cohesive state, the parts have their motion toward the center of the whole; the same holds for the world itself. Hence it is rightly said that all parts of the world have their motion toward its center, especially those that have weight. The same cause also accounts for the world’s remaining at rest in infinite void, and likewise for the earth’s being established in equilibrium about the world’s center.⁵⁴⁴

4 Zeno: Weightless bodies

A body does not necessarily have weight: air and fire are weightless. Yet these too tend in some way toward the center of the world’s entire sphere, while forming their mass toward its circumference; for they naturally move upward, since they have no share in weight.⁵⁴⁵

4 Zeno: The world and the earth

Similarly, they say that the world itself has no weight, because its entire constitution consists both of elements with weight and of weightless ones. They hold that the earth as a whole has weight in itself; but because of its position, occupying the central region, it remains in that place, since bodies of this kind move toward the center.⁵⁴⁶

5 ⟨Arius Didymus⟩: Apollodorus

Of Apollodorus. Apollodorus, in his Treatise on Physics, says that motion is a change in place or shape, in a whole or in [the] parts. Disposition is a holding together in place or shape, and being held in such a way.⁵⁴⁷ There are two primary kinds of motion, straight and circular; these have a number of species.⁵⁴⁸

5 Apollodorus: Simultaneous motions

Many motions can occur in the same thing and in the same place: for example, someone can walk and run without leaving that same place, and can move at once straight ahead, sideways, forward, backward, right, left, and in a circle, and both quickly and slowly at once, as happens with people sailing and others in similar circumstances.⁵⁴⁹

5 Apollodorus: Parts of motions

Just as we said that a part of every body is a body, of every surface a surface, of every line a line, of every place a place, and of every time a time, so we must say, by the same analogy, that a part of every motion is a motion and of every disposition a disposition.⁵⁵⁰

6 Plato: From the Parmenides

For if it were moving, it would either change place or undergo alteration, since these are the only kinds of motion?

Yes.⁵⁵¹

7 The same: From the Timaeus

Thus the living creature as a whole moved, but went wherever chance led, without order or reason, possessing all six motions: forward and backward, again right and left, downward and upward, wandering every way through the six directions.⁵⁵²

8 The same: From the Theaetetus

Tell me: do you call it motion when something passes from one place to another, or turns around in the same place?

I do.

Let this, then, be one kind. But when it remains in the same place and grows old, or changes from white to black, or from soft to hard, or undergoes some other alteration, ought we not to call that another kind of motion?

We certainly must.

I therefore distinguish these two kinds of motion: alteration, and revolution.⁵⁵³

9 In the same work: Being and becoming

I shall give an account that is far from trivial: nothing is one thing in itself, and you could not correctly call anything a definite thing or something of a definite quality. If you call something large, it will also appear small; if heavy, light; and so with everything, since nothing is one definite thing or has a definite quality. All things arise from locomotion, motion, and blending with one another. We wrongly speak of these things as “being”; for nothing ever is, but is always becoming.⁵⁵⁴

9 Plato: Poets and philosophers

On this all the wise agree, one after another, except Parmenides: Protagoras, Heraclitus, Empedocles, and the foremost poets in each kind of poetry, Epicharmus in comedy and Homer in tragedy.⁵⁵⁵ ⟨Homer, who⟩ said,

Ocean, origin of the gods, and mother Tethys,

said that all things are offspring of flow and motion. Who, then, could dispute with so great an army, with Homer as its general, and escape ridicule?⁵⁵⁶

That would not be easy, Socrates.

9 Plato: Motion and generation

Indeed not, Theaetetus. These too are sufficient signs in support of the account: motion produces what seems to be and what comes into being, whereas stillness produces nonbeing and destruction. For heat and fire, which generate and govern the other things, are themselves generated by movement and friction; that is motion. And the race of living creatures also springs from these same things.⁵⁵⁷

Of course.

9 Plato: Exercise of body and soul

And what of bodily condition? Is it not ruined by stillness and idleness, but generally preserved by exercise and motion?

Yes.

And the state of the soul: does it not acquire knowledge, preserve itself, and improve through learning and practice, which are motions, while through stillness, which is lack of practice and learning, it learns nothing and forgets whatever it has learned?

Certainly.

Then motion is the good for both soul and body, and the opposite is the contrary?

So it seems.⁵⁵⁸

9 Plato: The golden chain

Shall I also tell you of windless weather, calm seas, and the like: how these still conditions cause decay and destruction, while their opposites preserve? And, pressing the argument to its crowning point, shall I insist that by the golden chain Homer means nothing other than the sun?⁵⁵⁹ He shows that so long as the revolution and the sun continue moving, all things among gods and human beings exist and are preserved; but if this should come to a standstill, as though that were granted, everything would perish, and, as the saying goes, all would be turned upside down.⁵⁶⁰