Part 3

It appears to me that the difficulties and anomalies, in which we are involved from supposing that Aristotle either misunderstood or perverted the meaning of Plato--are far graver than those which would arise from admitting that Plato advanced a complicated theory involving two contradictory propositions, in the same dialogue, without perceiving the contradiction; more especially when the like failure of perception is indisputably ascribable to Aristotle--upon every view of the case.

M. Cousin maintains the same interpretation of the Platonic passage as Boeckh and Martin, and defends it by a note on his translation of the Timæus (p. 339). The five arguments which he produces are considered both by himself and by Martin to be unanswerable. As he puts them with great neatness and terseness, I here bestow upon them a separate examination.

1. "Platon a toujours été considéré dans l'antiquité comme partisan de l'immobilité absolue de la terre." M. Cousin had before said, "Aristote se fonde sur ce passage pour établir que Platon a fait tourner la terre sur elle-même: mais Aristote est, dans l'antiquité, le seul qui soutienne cette opinion."

My reply is, that Aristotle is himself a portion and member of antiquity, and that the various Platonists, whom he undertakes to refute, are portions of it also. If M. Cousin appeals to the authority of antiquity, it must be to antiquity, not merely minus Aristotle and these contemporary Platonists, but against them. Now these are just the witnesses who had the best means of knowledge. Besides which, Aristotle himself, adopting and anxious to demonstrate the immobility of the earth, had every motive to cite Plato as a supporter, if Plato was such--and every motive to avoid citing Plato as an opponent, unless the truth of the case compelled him to do so. I must here add, that M. Cousin represents Aristotle as ascribing to Plato the doctrine that "la terre tourne sur elle-même." This is not strictly exact. Aristotle understands the Platonic Timæus as saying, "That the earth is packed and moved round the axis of the kosmos"--a different proposition.

2. "Dans plusieurs endroits de ses ouvrages où Platon parle de l'équilibre de la terre, il ne dit pas un mot de sa rotation."

I know of only one such passage--Phædon, p. 108--where undoubtedly Plato does not speak of the rotation of the earth; but neither does he speak of the rotation of the sidereal sphere and of the kosmos--nor of the axis of the kosmos. It is the figure and properties of the earth, considered in reference to mankind who inhabit it, that Plato sketches in the Phædon; he takes little notice of its cosmical relations, and gives no general theory about the kosmos. M. Cousin has not adverted to the tenth Book of the Republic, where Plato does propound a cosmical theory, expressly symbolising the axis of the kosmos with its rotatory functions.

3. "Si la terre suit le mouvement de l'axe du monde, le mouvement de la huitième sphère, qui est Le Même, devient nul par rapport à elle, et les étoiles fixes, qui appartiennent à elle, demeurent en apparence dans une immobilité absolue: ce qui est contraire à l'expérience et au sens commun, et à l'opinion de Platon, exprimée dans ce même passage."

This third argument of M. Cousin is the same as that which I have already examined in remarking upon M. Boeckh. The diurnal rotation of the earth cannot stand in the same astronomical system with the diurnal rotation of the sidereal sphere. Incontestably true (I have already said) as a point of science. But the question here is, not what opinions are scientifically consistent, but what opinions were held by Plato, and whether he detected the inconsistency between the two. I have shown grounds for believing that he did not--and not he alone, but many others along with him, Aristotle among the number. How, indeed, can this be denied, when we find M. Boeckh announcing that he is the first among all the critics on the Timæus, who has brought forward the inconsistency as a special ground for determining what Plato's opinion was--that no other critic before him had noticed it?

The first words of this argument deserve particular attention, "Si la terre suit le mouvement de l'axe du monde." Here we have an exact recital of the doctrine proclaimed by the Platonic Timæus, and ascribed to him by Aristotle (quite different from the doctrine "que la terre tourne sur elle-même"). M. Cousin here speaks very distinctly about the cosmical axis, and about its movement; thus implying that Plato conceived it as a solid revolving cylinder. This, in my judgment, is the most essential point for clearing up the question in debate. The cosmical axis being of this character, when Plato affirms that the earth is packed or fastened round it (se roule--Cousin: se serre et s'enroule--Martin: drängt sich, macht eine Kugel um ihn--Buttmann), I maintain that, in the plainest construction of the word, the earth does and must follow the movement of the axis--or arrest the movement of the axis. The word [Greek: ei(lome/nên] or [Greek: i)llome/nên] has no distinct meaning at all, if it does not mean this. The very synonyms ([Greek: sphiggome/nên, peridedeme/nên], &c.), which the commentators produce to prove that Plato describes the earth as at rest, do really prove that he describes it as rotating round and with the cosmical axis. We ought not to be driven from this plain meaning of the word, by the assurance of M. Cousin and others that Plato cannot have meant so, because it would involve him in an astronomical inconsistency.

4. "Les divers mouvemens des huit sphères expliquent toutes les apparences célestes; il n'y a donc aucune raison pour donner un mouvement à la terre."

The terms of this fourth argument, if literally construed, would imply that Plato had devised a complete and satisfactory astronomical theory. I pass over this point, and construe them as M. Cousin probably intended: his argument will then stand thus--"The movement of the earth does not add anything to Plato's power of explaining astronomical appearances; therefore Plato had no motive to suggest a movement of the earth."

I have already specified the sense in which I understand the Platonic Timæus to affirm, or rather to imply, the rotation of the earth; and that sense is not open to the objections raised in M. Cousin's fourth and fifth arguments. The rotation of the earth, as it appears in the Platonic Timæus, explains nothing, and is not intended to explain anything. It is a consequence, not a cause: it is a consequence arising from the position of the earth, as packed or fastened round the centre of the cosmical axis, whereby the earth participates, of necessity and as a matter of course, in the movements of that axis. The function of the earth, thus planted in the centre of the kosmos, is to uphold and regulate the revolutions of the cosmical axis; and this function explains, in the scheme of the Platonic Timæus, why the axis revolves uniformly and constantly without change or displacement. Now upon these revolutions of the cosmical axis all the revolutions of the exterior sphere depend. This is admitted by M. Cousin himself in argument 3. There is therefore every reason why Plato should assign such regulating function to the earth, the "first and oldest of intra-kosmic deities." The movement of the earth (as I before observed) is only an incidental consequence of the position necessary for the earth to occupy in performing such function.

5. "Enfin Platon assigne un mouvement aux étoiles fixes, et deux mouvemens aux planètes; puisqu'il ne range la terre ni avec les unes ni avec les autres, il y a lieu de croire qu'elle ne participe à aucun de leurs mouvemens."

In so far as this argument is well-founded, it strengthens my case more than that of M. Cousin. The earth does not participate in the movements either of the fixed stars or of the planets; but it does participate in the revolutions of the cosmical axis, upon which these movements depend--the movements of the outer sphere, wholly and exclusively--the movements of the planets, to a very great degree, but not exclusively. The earth is not ranked either among the fixed stars or among the planets; it is a body or deity sui generis, having a special central function of its own, to regulate that cosmical axis which impels the whole system. The earth has a motion of its own, round and along with the cosmical axis to which it is attached; but this motion of the earth (I will again repeat, to prevent misapprehension) is a fact not important by itself, nor explaining anything. The grand and capital fact is the central position and regulating function of the earth, whereby all the cosmical motions, first those of the axis, next those of the exterior kosmos, are upheld and kept uniform.

M. Cousin adds, as a sixth argument:--

"On peut ajouter à ces raisons que Platon aurait nécessairement insisté sur le mouvement de la terre, s'il l'avait admis; et que ce point étoit trop controversé de son temps et trop important en lui-même, pour qu'il ne fît que l'indiquer en se servant d'une expression équivoque."

In the first place, granting Plato to have believed in the motion of the earth, can we also assume that he would necessarily have asserted it with distinctness and emphasis, as M. Cousin contends? I think not. Gruppe maintains exactly the contrary; telling us that Plato's language was intentionally obscure and equivocal--from fear of putting himself in open conflict with the pious and orthodox sentiment prevalent around him. I do not carry this part of the case so far as Gruppe, but I admit that it rests upon a foundation of reality. When we read (Plutarch, De Facie in Orbe Lunæ, p. 923) how the motion of the earth, as affirmed by Aristarchus of Samos (doubtless in a far larger sense than Plato ever imagined, including both rotation and translation), was afterwards denounced as glaring impiety, we understand the atmosphere of religious opinion with which Plato was surrounded. And we also perceive that he might have reasons for preferring to indicate an astronomical heresy in terms suitable for philosophical hearers, rather than to proclaim it in such emphatic unequivocal words, as might be quoted by some future Melêtus in case of an indictment before the Dikasts.

We must remember that Plato had been actually present at the trial of Sokrates. He had heard the stress laid by the accusers on astronomical heresies, analogous to those of Anaxagoras, which they imputed to Sokrates--and the pains taken by the latter to deny that he held such opinions (see the Platonic Apology). The impression left by such a scene on Plato's mind was not likely to pass away: nor can we be surprised that he preferred to use propositions which involved and implied, rather than those which directly and undisguisedly asserted, the heretical doctrine of the earth's rotation. That his phraseology, however indirect, was perfectly understood by contemporary philosophers, both assentient and dissentient, as embodying his belief in the doctrine--is attested by the two passages of Aristotle.

Upon these reasons alone I should dissent from M. Cousin's sixth argument. But I have other reasons besides. He rests it upon the two allegations that the doctrine of the earth's motion was the subject of much controversial debate in Plato's time, and of great importance in itself. Now the first of these two allegations can hardly be proved, as to the time of Plato; for Aristotle, when he is maintaining the earth's immobility, does not specify any other opponents than the Pythagoreians and the followers of the Platonic Timæus. And the second allegation I believe to be unfounded, speaking with reference to the Platonic Timæus. In the cosmical system therein embodied, the rotation of the earth round the cosmical axis, though a real part of the system, was in itself a fact of no importance, and determining no results. The capital fact of the system was the position and function of the earth, packed close round the centre of the cosmical axis, and regulating the revolutions of that axis. Plato had no motive to bring prominently forward the circumstance that the earth revolved itself along with the cosmical axis, which circumstance was only an incidental accompaniment.

I have thus examined all the arguments adduced by M. Cousin, and have endeavoured to show that they fail in establishing his conclusion. There is, however, one point of the controversy in which I concur with him more than with Boeckh and Martin. This point is the proper conception of what Plato means by the cosmical axis. Boeckh and Martin seem to assume this upon the analogy of what is now spoken of as the axis of the earth: M. Boeckh (p. 13) declares the axis of the kosmos to be a prolongation of that axis. But it appears to me (and M. Cousin's language indicates the same) that Plato's conception was something very different. The axis of the earth (what astronomers speak of as such) is an imaginary line traversing the centre of the earth; a line round which the earth revolves. Now the cosmical axis, as Plato conceives it, is a solid material cylinder, which not only itself revolves, but causes by this revolution the revolution of the exterior circumference of the kosmos. This is a conception entirely different from that which we mean when we speak of the axis of the earth. It is, however, a conception symbolically enunciated in the tenth book of the Republic, where the spindle of Necessity is said to be composed of adamant, hard and solid material, and to cause by its own rotation the rotation of all the verticilli packed and fastened around it. What is thus enunciated in the Republic is implied in the Timæus. For when we read therein that the earth is packed or fastened round the cosmical axis, how can we understand it to be packed or fastened round an imaginary line? I will add that the very same meaning is brought out in the translation of Cicero--"trajecto axe sustinetur" (terra). The axis, round which the earth is fastened, and which sustains the earth, must be conceived, not as an imaginary line, but as a solid cylinder, itself revolving; while the earth, being fastened round it, revolves round and along with it. The axis, in the sense of an imaginary line, cannot be found in the conception of Plato.

Those contemporaries of Plato and Aristotle, who all agreed in asserting the revolution of the celestial sphere, did not all agree in their idea of the force whereby such revolution was brought about. Some thought that the poles of the celestial sphere exercised a determining force: others symbolised the mythical Atlas, as an axis traversing the sphere from pole to pole and turning it round. (Aristotel. De Motu Animal. 3. p. 699 a. 15-30.) Aristotle himself advocated the theory of a primum movens immobile acting upon the sphere from without the sphere. Even in the succeeding centuries, when astronomy was more developed, Aratus, Eratosthenes, and their commentators, differed in their way of conceiving the cosmical axis. Most of them considered it as solid: but of these, some thought it was stationary, with the sphere revolving round it--others that it revolved itself: again, among these latter, some believed that the revolutions of the axis determined those of the surrounding sphere--others, that the revolutions of the sphere caused those of the axis within it. Again, there were some physical philosophers who looked at the axis as airy or spiritual--[Greek: to\ dia\ me/sou tê=s sphai/ras diê=kon pneu=ma]. Then there were geometers who conceived it only as an imaginary line. (See the Phaenomena of Aratus 20-25--with the Scholia thereon; Achilles Tatius ad Arati Phaenom. apud Petavium--Uranolog. p. 88; also Hipparchus ad Arat. ib. p. 144.) I do not go into these dissentient opinions farther than to show, how indispensable it is, when we construe the passage in the Platonic Timaeus, [Greek: peri\ to\n dia\ panto\s po/lon tetame/non], to enquire in what sense Plato understood the cosmical axis: and how unsafe it is to assume at once that he must have conceived it as an imaginary line.

Proklus argues that because the earth is mentioned by Plato in the Phædon as stationary in the centre of the heaven, we cannot imagine Plato to affirm its rotation in the Timæus. I agree with M. Boeckh in thinking this argument inconclusive; all the more, because, in the Phædon, not a word is said either about the axis of the kosmos, or about the rotation of the kosmos; all that Sokrates professes to give is [Greek: tê\n i)de/an tê=s gê=s kai\ tou\s to/pous au)tê=s**] (p. 108 E). No cosmical system or theory is propounded in that dialogue.

When we turn to the Phædrus, we find that, in its highly poetical description, the rotation of the heaven occupies a prominent place. The internal circumference of the heavenly sphere, as well as its external circumference or back ([Greek: nô=ton]), are mentioned; also its periodical rotations, during which the gods are carried round on the back of the heaven, and contemplate the eternal Ideas occupying the super-celestial space (p. 247, 248), or the plain of truth. But the purpose of this poetical representation appears to be metaphysical and intellectual, to illustrate the antithesis presented by the world of Ideas and Truth on one side--against that of sense and appearances on the other. Astronomically and cosmically considered, no intelligible meaning is conveyed. Nor can we even determine whether the rotations of the heaven, alluded to in the Phædrus, are intended to be diurnal or not; I incline to believe not ([Greek: me/chri tê=s e(te/ras perio/dou]--p. 248--which can hardly be understood of so short a time as one day). Lastly, nothing is said in the Phædrus about the cosmical axis; and it is upon this that the rotations of the earth intimated in the Timæus depend.

Among the different illustrations, given by Plato in his different dialogues respecting the terrestrial and celestial bodies, I select the tenth book of the Republic as that which is most suitable for comparison with the Timæus, because it is only therein that we learn how Plato conceived the axis of the kosmos. M. Boeckh (Untersuchungen, p. 86) wishes us to regard the difference between the view taken in the Phædon, and that in the Republic, as no way important; he affirms that the adamantine spindle in the Republic is altogether mythical or poetical, and that Plato conceives the axis as not being material. On this point I dissent from M. Boeckh. The mythical illustrations in the tenth book of the Republic appear to me quite unsuitable to the theory of an imaginary, stationary, and immaterial axis. Here I much more agree with Gruppe (p. 15, 26-29), who recognises the solid material axis as an essential feature of the cosmical theory in the Republic; and recognises also the marked difference between that theory and what we read in the Phædon. Yet, though Gruppe is aware of this important difference between the Republic and the Phædon, he still wishes to illustrate the Timæus by the latter and not by the former. He affirms that the earth in the Timæus is conceived as unattached, and freely suspended, the same as in the Phædon; but that in the Timæus it is conceived, besides, as revolving on its own axis, which we do not find in the Phædon (p. 28, 29). Here I think Gruppe is mistaken. In construing the words of Timæus, [Greek: ei(lome/nên (i)llome/nên) peri\ to\n dia\ panto\s po/lon tetame/non], as designating "the unattached earth revolving round its own axis," he does violence not less to the text of Plato than to the expository comment of Aristotle. Neither in the one nor the other is anything said about an axis of the earth; in both, the cosmical axis is expressly designated; and, if Gruppe is right in his interpretation of [Greek: ei(lome/nên], we must take Plato as affirming, not that the earth is fastened round the cosmical axis, but that it revolves, though unattached, around that axis, which is a proposition both difficult to understand, and leading to none of those astronomical consequences with which Gruppe would connect it. Again, when Gruppe says that [Greek: ei(lome/nên peri\] does not mean packed or fastened round, but that it does mean revolving round, he has both the analogies of the word and the other commentators against him. The main proof, if not the only proof, which he brings, is that Aristotle so construed it. Upon this point I join issue with him. I maintain that Aristotle does not understand [Greek: ei(lome/nên] or [Greek: i)llome/nên peri\] as naturally meaning revolving round, and that he does understand the phrase as meaning fastened round. When we find him, in the second passage of the treatise De Coelo, not satisfied with the verb [Greek: i)/llesthai] alone, but adding to it the second verb [Greek: kai\ kinei=sthai], we may be sure that he did not consider [Greek: i)/llesthai] as naturally and properly denoting to revolve or move round.

Agreeing as I do with Gruppe in his view, that the interpretation put by Aristotle is the best evidence which we can follow in determining the meaning of this passage in the Timæus, I contend that the authority of Aristotle contradicts instead of justifying the conclusion at which he arrives. Aristotle understands [Greek: i)llome/nên] as meaning packed or fastened round; he does not understand it as meaning, when taken by itself, revolving round.

The two meanings here indicated are undoubtedly distinct and independent. But they are not for that reason contradictory and incompatible. It has been the mistake of critics to conceive them as thus incompatible; so that if one of the two were admitted, the other must be rejected. I have endeavoured to show that this is not universally true, and that there are certain circumstances in which the two meanings not only may come together, but must come together. Such is the case when we revert to Plato's conception of the cosmical axis as a solid revolving cylinder. That which is packed or fastened around the cylinder must revolve around it, and along with it.

Both M. Boeckh and Gruppe assume the incompatibility of the two meanings; and we find the same assumption in Plutarch's criticisms on the Timæus (Plutarch. Quæst. Platon. p. 1006 C), where he discusses what Plato means by [Greek: o)/rgana chro/nou]; and in what sense the earth as well as the moon can be reckoned as [Greek: o)/rganon chro/nou] (Timæus, p. 41 E, 42 D). Plutarch inquires how it is possible that the earth, if stationary and at rest, can be characterised as "among the instruments of time;" and he explains it by saying that this is true in the same sense as we call a gnomon or sun-dial an instrument of time, because, though itself never moves, it marks the successive movements of the shadow. This explanation might be admissible for the phrase [Greek: o)/rganon chro/nou]; but I cannot think that the immobility of the earth can be made compatible with the attribute which Plato bestows upon it of being [Greek: phu/lax kai\ dêmiourgo\s nukto\s te kai\ ê(me/ras].

The difficulty, however, vanishes when we understand the function ascribed by Plato to the earth as I have endeavoured to elucidate it. The earth not only is not at rest, but cannot be at rest, precisely because it is packed round the solid revolving cosmical axis, and must revolve along with it. The function of the earth, as the first and oldest of intra-kosmic deities, is to uphold and regulate the revolutions of this axis, upon which depend the revolutions of the sidereal sphere or outer shell of the kosmos. It is by virtue of this regulating function (and not by virtue of its rotation) that the earth is the guardian and artificer of night and day. It is not only "an instrument of time," but the most potent and commanding among all instruments of time.