II. Diogenes of Apollonia
Date.
186. After discussing the three great representatives of the Milesian school, Theophrastos went on to say:
And Diogenes of Apollonia, too, who was almost the latest of those who gave themselves up to these studies, wrote most of his work in an eclectic fashion, agreeing in some points with Anaxagoras and in others with Leukippos. He, too, says that the primary substance of the universe is Air infinite and eternal, from which by condensation, rarefaction, and change of state, the form of everything else arises. R. P. 206 a.[[996]]
This passage shows that the Apolloniate was somewhat later in date than the statement in Laertios Diogenes[[997]] that he was contemporary with Anaxagoras would lead us to suppose, and the fact that he is satirised in the Clouds of Aristophanes points in the same direction.[[998]] Of his life we know next to nothing. He was the son of Apollothemis, and came from Apollonia in Crete.[[999]] The Ionic dialect in which he wrote is no objection to this; it was the regular dialect for cosmological works.[[1000]]
The fact that Diogenes was parodied in the Clouds suggests that he had found his way to Athens; and we have the excellent authority of Demetrios Phalereus[[1001]] for saying that the Athenians treated him in the usual way. He excited so great dislike as nearly to imperil his life.
Writings.
187. Simplicius affirms that Diogenes wrote several works, though he allows that only one survived till his own day, namely, the Περὶ φύσεως.[[1002]] This statement is based upon references in the surviving work itself, and is not to be lightly rejected. In particular, it is very credible that he wrote a tract Against the Sophists, that is to say, the pluralist cosmologists of the day.[[1003]] That he wrote a Meteorology and a book called The Nature of Man is also quite probable. This would be a physiological or medical treatise, and perhaps the famous fragment about the veins comes from it.[[1004]]
The Fragments.
188. The work of Diogenes seems to have been preserved in the Academy; practically all the fairly extensive fragments which we still have are derived from Simplicius. I give them as they are arranged by Diels:—
(1) In beginning any discourse, it seems to me that one should make one’s starting-point something indisputable, and one’s expression simple and dignified. R. P. 207.
(2) My view is, to sum it all up, that all things are differentiations of the same thing, and are the same thing. And this is obvious; for, if the things which are now in this world—earth, and water, and air and fire, and the other things which we see existing in this world,—if any one of these things, I say, were different from any other, different, that is, by having a substance peculiar to itself; and if it were not the same thing that is often changed and differentiated, then things could not in any way mix with one another, nor could they do one another good or harm. Neither could a plant grow out of the earth, nor any animal nor anything else come into being unless things were composed in such a way as to be the same. But all these things arise from the same thing; they are differentiated and take different forms at different times, and return again to the same thing. R. P. 208.
(3) For it would not be possible for it to be divided as it is without intelligence, so as to keep the measures of all things, of winter and summer, of day and night, of rains and winds and fair weather. And any one who cares to reflect will find that everything else is disposed in the best possible manner. R. P. 210.
(4) And, further, there are still the following great proofs. Men and all other animals live upon air by breathing it, and this is their soul and their intelligence, as will be clearly shown in this work; while, when this is taken away, they die, and their intelligence fails. R. P. 210.
(5) And my view is, that that which has intelligence is what men call air, and that all things have their course steered by it, and that it has power over all things. For this very thing I hold to be a god,[[1005]] and to reach everywhere, and to dispose everything, and to be in everything; and there is not anything which does not partake in it. Yet no single thing partakes in it just in the same way as another; but there are many modes both of air and of intelligence. For it undergoes many transformations, warmer and colder, drier and moister, more stable and in swifter motion, and it has many other differentiations in it, and an infinite number of colours and savours. And the soul of all living things is the same, namely, air warmer than that outside us and in which we are, but much colder than that near the sun. And this warmth is not alike in any two kinds of living creatures, nor, for the matter of that, in any two men; but it does not differ much, only so far as is compatible with their being alike. At the same time, it is not possible for any of the things which are differentiated to be exactly like one another till they all once more become the same.
(6) Since, then, differentiation is multiform, living creatures are multiform and many, and they are like one another neither in appearance nor in intelligence, because of the multitude of differentiations. At the same time, they all live, and see, and hear by the same thing, and they all have their intelligence from the same source. R. P. 211.
(7) And this itself is an eternal and undying body, but of those things[[1006]] some come into being and some pass away.
(8) But this, too, appears to me to be obvious, that it is both great, and mighty, and eternal, and undying, and of great knowledge. R. P. 209.
That the chief interest of Diogenes was a physiological one, is clear from his elaborate account of the veins, preserved by Aristotle.[[1007]] It is noticeable, too, that one of his arguments for the underlying unity of all substances is that without this it would be impossible to understand how one thing could do good or harm to another (fr. [2]). In fact, the writing of Diogenes is essentially of the same character as a good deal of the pseudo-Hippokratean literature, and there is much to be said for the view that the writers of these curious tracts made use of him very much as they did of Anaxagoras and Herakleitos.[[1008]]
Cosmology.
189. Like Anaximenes, Diogenes regarded Air as the primary substance; but we see from his arguments that he lived at a time when other views had become prevalent. He speaks clearly of the four Empedoklean elements (fr. [2]), and he is careful to attribute to Air the attributes of Nous as taught by Anaxagoras (fr. [4]). The doxographical tradition as to his cosmological views is fairly preserved:—
Diogenes of Apollonia makes air the element, and holds that all things are in motion, and that there are innumerable worlds. And he describes the origin of the world thus. When the All moves and becomes rare in one place and dense in another, where the dense met together it formed a mass, and then the other things arose in the same way, the lightest parts occupying the highest position and producing the sun. [Plut.] Strom. fr. 12 (R. P. 215).
Nothing arises from what is not nor passes away into what is not. The earth is round, poised in the middle, having received its shape through the revolution proceeding from the warm and its solidification from the cold. Diog. ix. 57 (R. P. 215).
The heavenly bodies were like pumice-stone. He thinks they are the breathing-holes of the world, and that they are red-hot. Aet. ii. 13, 5 = Stob. i. 508 (R. P. 215).
The sun was like pumice-stone, and into it the rays from the aether fix themselves. Aet. ii. 20, 10. The moon was a pumice-like conflagration. Ib. ii. 25, 10.
Along with the visible heavenly bodies revolve invisible stones, which for that very reason are nameless; but they often fall and are extinguished on the earth like the stone star which fell down flaming at Aigospotamos.[[1009]] Ib. ii. 13, 9.
We have here nothing more than the old Ionian doctrine with a few additions from more recent sources. Rarefaction and condensation still hold their place in the explanation of the opposites, warm and cold, dry and moist, stable and mobile (fr. [5]). The differentiations into opposites which Air may undergo are, as Anaxagoras had taught, infinite in number; but all may be reduced to the primary opposition of rare and dense. We may gather, too, from Censorinus[[1010]] that Diogenes did not, like Anaximenes, speak of earth and water as arising from Air by condensation, but rather of blood, flesh, and bones. In this he followed Anaxagoras ([§ 130]), as it was natural that he should. That portion of Air, on the other hand, which was rarefied became fiery, and produced the sun and heavenly bodies. The circular motion of the world is due to the intelligence of the Air, as is also the division of all things into different forms of body and the observance of the “measures” by these forms.[[1011]]
Like Anaximander ([§ 20]), Diogenes regarded the sea as the remainder of the original moist state, which had been partially evaporated by the sun, so as to separate out the remaining earth.[[1012]] The earth itself is round, that is to say, it is a disc: for the language of the doxographers does not point to the spherical form.[[1013]] Its solidification by the cold is due to the fact that cold is a form of condensation.
Diogenes did not hold with the earlier cosmologists that the heavenly bodies were made of air or fire, nor yet with Anaxagoras, that they were stones. They were, he said, pumice-like, a view in which we may trace the influence of Leukippos. They were earthy, indeed, but not solid, and the celestial fire permeated their pores. And this explains why we do not see the dark bodies which, in common with Anaxagoras, he held to revolve along with the stars. They really are solid stones, and therefore cannot be penetrated by the fire. It was one of these that fell into the Aigospotamos. Like Anaxagoras, Diogenes affirmed that the inclination of the earth happened subsequently to the rise of animals.[[1014]]
We are prepared to find that Diogenes held the doctrine of innumerable worlds; for it was the old Milesian belief, and had just been revived by Anaxagoras and Leukippos. He is mentioned with the rest in the Placita; and if Simplicius classes him and Anaximenes with Herakleitos as holding the Stoic doctrine of successive formations and destructions of a single world, he has probably been misled by the “accommodators.”[[1015]]
Animals and plants.
190. Living creatures arose from the earth, doubtless under the influence of heat. Their souls, of course, were air, and their differences were due to the various degrees in which it was rarefied or condensed (fr. [5]). No special seat, such as the heart or the brain, was assigned to the soul; it was simply the warm air circulating with the blood in the veins.
The views of Diogenes as to generation, respiration, and the blood, belong to the history of Medicine;[[1016]] his theory of sensation too, as it is described by Theophrastos,[[1017]] need only be mentioned in passing. Briefly stated, it amounts to this, that all sensation is due to the action of air upon the brain and other organs, while pleasure is aeration of the blood. But the details of the theory can only be studied properly in connexion with the Hippokratean writings; for Diogenes does not really represent the old cosmological tradition, but a fresh development of reactionary philosophical views combined with an entirely new enthusiasm for detailed investigation and accumulation of facts.