Thales was the first to declare the soul to be always in motion, or self-moving.
Pythagoras calls it a number that moves itself, taking number to stand for intellect.
Xenocrates holds the same view.
Alcmaeon considers it a nature that moves itself in eternal motion, and for this reason regards it as immortal and akin to divine things.1248
1a.2 · Harmony and the senses
I.49.1a.2 · Wachsmuth pp. 319
Dicaearchus calls it a harmony of the four elements.
Asclepiades the physician calls it the joint exercise of the senses.1249
1a.3 · Aristotle: first actuality
I.49.1a.3 · Wachsmuth pp. 319
Aristotle calls it the first actuality of a natural body equipped with organs and possessing life potentially. “Actuality” is to be understood as form and activity.1250
1b.1 · ⟨Aëtius⟩: air, breath, and fire
I.49.1b.1 · Wachsmuth pp. 319
Anaximenes, Anaxagoras, Archelaus, [Diogenes] call it air-like.
Xenarchus the Peripatetic and certain others of the same school call it perfection and actuality in respect of form, existing in its own right and at the same time ordered together with the body.1254
1b.4 · Epicurus: a fourfold mixture
I.49.1b.4 · Wachsmuth pp. 320
Epicurus calls it a mixture of four constituents: something fiery, something airy, something breath-like, and a fourth, unnamed constituent. This last was, for him, the element responsible for perception. Of these constituents, breath produces motion; air, rest; the warm constituent, the manifest warmth of the body; and the unnamed constituent, perception within us. For perception is present in none of the elements that have names.1255
1c · Hermes: soul as thinking substance
I.49.1c · Wachsmuth pp. 320
From Hermes.
Soul, then, is an eternal substance capable of thought, having its own reason as its object of thought.1256
2 · Plato: a shortened quotation
I.49.2 · Wachsmuth pp. 320
From Plato, from the Phaedrus.
For the colorless, shapeless, intangible substance of soul, truly ⟨existing⟩.1257
3.1 · Hermes: body depends upon soul
I.49.3.1 · Wachsmuth pp. 320-321
From Hermes.
Soul, then, is an incorporeal substance. For if it has a body, it will no longer be able to preserve itself. Every body needs being; it also needs life established in an orderly arrangement. Everything that comes into being must also undergo change. What comes into being does so with magnitude; ⟨for⟩ in coming into being it grows. Everything that grows is followed by diminution, and diminution by destruction. But through receiving a form of life it lives and shares in being ⟨through⟩ soul.1258
3.2 · The source of rational life
I.49.3.2 · Wachsmuth pp. 321
What causes another thing to be is itself already a being. By “being” here I mean coming to exist in reason and sharing in intelligent life; it is soul that supplies intelligent life. It is called a living creature because of life, rational because of intelligence, and mortal because of the body. Soul, therefore, is an incorporeal ⟨substance⟩ whose power does not change. How can one speak of an [intelligent] living creature unless there is a substance that also supplies life? Nor can one call it rational unless there is a thinking substance that also supplies intelligent life.1259
3.3 · Bodily constitution and intelligence
I.49.3.3 · Wachsmuth pp. 321
Intelligence does not reach everyone, because of the body’s constitution in relation to its harmony. If warmth predominates in the constitution, the ⟨person⟩ becomes light and ardent; if cold predominates, heavy and sluggish. For nature adjusts the constitution of the body to its harmony. There are three forms of harmony: that according to warmth, that according to cold, and that according to the intermediate condition.1260
3.4 · The harmony of the stars
I.49.3.4 · Wachsmuth pp. 321
Nature adjusts it according to the star that has prevailed in the blending of the stars. Soul receives a ⟨body⟩ as fate has ordained and gives life to this work of nature. Nature therefore makes the body’s harmony resemble the blending of the stars and unifies its many mixed constituents in accordance with the stars’ harmony, so that they have sympathy with one another. For the purpose of the stars’ harmony is to engender sympathy according to their fate.1261