



Produced by Ed Brandon as part of the on-line Grote Project








PLATO'S DOCTRINE

RESPECTING THE

ROTATION OF THE EARTH,

AND

ARISTOTLE'S COMMENT UPON THAT DOCTRINE.


BY GEORGE GROTE, ESQ.


LONDON:
JOHN MURRAY, ALBEMARLE STREET.
1860.

_The right of Translation is reserved._


LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET,
AND CHARING CROSS.




EXAMINATION OF THE THREE FOLLOWING QUESTIONS:--

1. WHETHER THE DOCTRINE OF THE EARTH'S ROTATION IS AFFIRMED OR
IMPLIED IN THE PLATONIC TIMAEUS?

2. IF AFFIRMED OR IMPLIED, IN WHAT SENSE?

3. WHAT IS THE COSMICAL FUNCTION WHICH PLATO ASSIGNS TO THE EARTH
IN THE TIMAEUS?




PREFACE.

The following paper was originally intended as an explanatory note
on the Platonic Timaeus, in the work which I am now preparing on
Plato and Aristotle. Interpreting, differently from others, the
much debated passage in which Plato describes the cosmical
function of the Earth, I found it indispensable to give my reasons
for this new view. But I soon discovered that those reasons could
not be comprised within the limits of a note. Accordingly I here
publish them in a separate Dissertation. The manner in which the
Earth's rotation was conceived, illustrates the scientific
character of the Platonic and Aristotelian age, as contrasted with
the subsequent development and improvement of astronomy.




PLATO--ON THE EARTH'S ROTATION.


In Plato, Timaeus, p. 40 B, we read the following words--[Greek:
Ge=n de\ tropho\n me\n e(mete/ran, ei(llome/nen de\ peri\ to\n
dia\ panto\s po/lon tetame/non phu/laka kai\ demiourgo\n nukto/s
te kai\ e(me/ras e)mechane/sato, pro/ten kai\ presbuta/ten theo=n,
o(/soi e)nto\s ou)ra/nou gego/nasi.] I give the text as it stands
in Stallbaum's edition.

The obscurity of this passage is amply attested by the numerous
differences of opinion to which it has given rise, both in ancient
and in modern times. Various contemporaries of Plato ([Greek:
e)/nioi]--Aristot. De Coelo, II. 13, p. 293 b. 30) understood it
as asserting or implying the rotatory movement of the earth in the
centre of the Kosmos, and adhered to this doctrine as their own.
Aristotle himself alludes to these contemporaries without naming
them, and adopts their interpretation of the passage; but dissents
from the doctrine, and proceeds to impugn it by arguments. Cicero
mentions (Academic II. 39) that there were persons who believed
Plato to have indicated the same doctrine obscurely, in his
Timaeus: this passage must undoubtedly be meant. Plutarch devotes
a critical chapter to the enquiry, what was Plato's real doctrine
as to the cosmical function of the earth--its movement or rest
(Quaestion. Platonic. VII. 3, p. 1006.)

There exists a treatise, in Doric dialect, entitled [Greek:
Ti/maio** to= Lo/kro Peri\ Psucha=s Ko/smo kai\
Phu/sios], which is usually published along with the works of Plato.
This treatise was supposed in ancient times to be a genuine production
of the Lokrian Timaeus, whom Plato introduces as his spokesman in the
dialogue so called. As such, it was considered to be of much
authority in settling questions of interpretation as to the
Platonic Timaeus. But modern critics hold, I believe unanimously,
that it is the work of some later Pythagorean or Platonist,
excerpted or copied from the Platonic Timaeus. This treatise
represents the earth as being in the centre and at rest. But its
language, besides being dark and metaphorical, departs widely from
the phraseology of the Platonic Timaeus: especially in this--that
it makes no mention of the cosmical axis, nor of the word
[Greek: i)llome/nen] or [Greek: ei(loume/nen].

Alexander of Aphrodisias (as we learn from Simplikius ad Aristot.
De Coelo, fol. 126) followed the construction of Plato given by
Aristotle. "It was improbable (he said) that Aristotle could be
ignorant either what the word signified, or what was Plato's
purpose" ([Greek: a)lla\ to=| A)ristote/lei, phesi\n, ou(/to
le/gonti _i)/llesthai_, ou)k eu)/logon a)ntile/gein; o(s
a)letho=s ga\r ou)/te te=s le/xeos to\ semaino/menon ei)ko\s e)=n
a)gnoei=n au)to\n, ou)/te to\n Pla/tonos skopo/n.] This passage is
not given in the Scholia of Brandis). Alexander therefore
construed [Greek: i)llome/nen] as meaning or implying rotatory
movement, though in so doing he perverted (so Simplikius says) the
true meaning to make it consonant with his own suppositions.

Proklus maintains that Aristotle has interpreted the passage
erroneously,--that [Greek: i)llome/nen] is equivalent to [Greek:
sphiggome/nen] or [Greek: xunechome/nen]--and that Plato intends
by it to affirm the earth as at rest in the centre of the Kosmos
(ad Timaeum, Book iv., p. 681 ed. Schneider). Simplikius himself
is greatly perplexed, and scarcely ventures to give a positive
opinion of his own. On the whole, he inclines to believe that
[Greek: i)llome/nen] might possibly be understood, by superficial
readers, so as to signify rotation, though such is not its proper
and natural sense: that some Platonists did so misunderstand it:
and that Aristotle accepted their sense for the sake of the
argument, without intending himself to countenance it (ad Aristot.
De Coelo, p. 126).

Both Proklus and Simplikius, we must recollect, believed in the
genuineness of the Doric treatise ascribed to Timaeus Locrus.
Reasoning upon this basis, they of course saw, that if Aristotle
had correctly interpreted Plato, Plato himself must have
interpreted _incorrectly_ the doctrine of Timaeus. They had
to ascribe wrong construction either to Plato or to Aristotle: and
they could not bear to ascribe it to Plato.

Alkinous, in his Eisagoge (c. 15) gives the same interpretation as
Proklus. But it is remarkable that in his paraphrase of the
Platonic words, he calls the earth [Greek: e(me/ras phu/lax kai\
nukto/s]: omitting the significant epithet [Greek: demiourgo/s].

In regard to modern comments upon the same disputed point, I need
only mention (besides those of M. Cousin, in the notes upon his
translation of the 'Timaeus', and of Martin in his 'Etudes sur le
Timee') the elaborate discussion which it has received in the two
recent Dissertations 'Ueber die kosmischen Systeme der Griechen,'
by Gruppe and Boeckh. Gruppe has endeavoured, upon the evidence
of this passage, supported by other collateral proofs, to show
that Plato, towards the close of his life, arrived at a belief,
first, in the rotation of the earth round its own axis, next, at
the double movement of the earth, both rotation and translation,
round the sun as a centre (that is, the heliocentric or Copernican
system): that Plato was the first to make this discovery, but that
he was compelled to announce it in terms intentionally equivocal
and obscure, for fear of offending the religious sentiments of his
contemporaries ('Die kosmischen Systeme der Griechen, von O. F.
Gruppe,' Berlin, 1851). To this dissertation M. Boeckh--the
oldest as well as the ablest of all living philologists--has
composed an elaborate reply, with his usual fulness of
illustrative matter and sobriety of inference. Opinions previously
delivered by him (in his early treatises on the Platonic and
Pythagoreian philosophy) had been called in question by Gruppe: he
has now re-asserted them and defended them at length, maintaining
that Plato always held the earth to be stationary and the sidereal
sphere rotatory--and answering or extenuating the arguments which
point to an opposite conclusion ('Untersuchungen ueber das
kosmische System des Platon, von August Boeckh,' Berlin, 1852).

Gruppe has failed in his purpose of proving that Plato adopted
either of the two above-mentioned doctrines--either the rotation
of the earth round its own axis, or the translation of the earth
round the sun as a centre. On both these points I concur with
Boeckh in the negative view. But though I go along with his reply
as to its negative results, I cannot think it satisfactory in its
positive aspect as an exposition of the doctrine proclaimed in the
Platonic Timaeus: nor can I admit that the main argument of M.
Boeckh's treatise is sufficient to support the inference which he
rests upon it. Moreover, he appears to me to set aside or explain
away too lightly the authority of Aristotle. I agree with
Alexander of Aphrodisias and with Gruppe who follows him, in
pronouncing Aristotle to be a good witness, when he declares what
were the doctrines proclaimed in the Platonic Timaeus; though I
think that Gruppe has not accurately interpreted either Timaeus or
Aristotle.

The capital argument of Boeckh is as follows: "The Platonic Timaeus
affirms, in express and unequivocal terms, the rotation of the
outer celestial sphere (the sidereal sphere or Aplanes) in
twenty-four hours, as bringing about and determining the succession
of day and night. Whoever believes this cannot at the same time
believe that the earth revolves round its own axis in twenty-four
hours, and that the succession of day and night is determined
thereby. The one of these two affirmations excludes the other;
and, as the first of the two is proclaimed, beyond all possibility
of doubt, in the Platonic Timaeus, so we may be sure that the
second of the two cannot be proclaimed in that same discourse. If
any passage therein seems to countenance it, we must look for some
other mode of interpreting the passage."

This is the main argument of M. Boeckh, and also of Messrs. Cousin
and Martin. The latter protests against the idea of imputing to
Plato "un melange monstrueux de deux systemes incompatibles"
(Etudes sur le Timee, vol. ii. p. 86-88).

As applied to any person educated in the modern astronomy, the
argument is irresistible. But is it equally irresistible when
applied to Plato and to Plato's time? I think not. The
incompatibility which appears so glaring at present, did not
suggest itself to him or to his contemporaries. To prove this we
have only to look at the reasoning of Aristotle, who (in the
treatise De Coelo, ii. 13-14, p. 293. b. 30, 296. a. 25) notices
and controverts the doctrine of the rotation of the earth, with
express reference to the followers of the Platonic Timaeus--and who
(if we follow the view of Martin) imputes this doctrine with
wilful falsehood to Plato, for the purpose of contemptuously
refuting it "pour se donner le plaisir de la refuter avec dedain."
Granting the view of M. Boeckh (still more that of Martin) to be
correct, we should find Aristotle arguing thus:--"Plato affirms
the diurnal rotation of the earth round the centre of the cosmical
axis. This is both incredible, and incompatible with his own
distinct affirmation that the sidereal sphere revolves in
twenty-four hours. It is a glaring inconsistency that the same author
should affirm both the one and the other." Such would have been
Aristotle's reasoning, on the hypothesis which I am considering;
but when we turn to his treatise we find that he does not employ
this argument at all. He contests the alleged rotation of the
earth upon totally different arguments--chiefly on the ground that
rotatory motion is not natural to the earth, that the kind of
motion natural to the earth is rectilineal, towards the centre;
and he adds various corollaries flowing from this doctrine which I
shall not now consider. At the close of his refutation, he states
in general terms that the celestial appearances, as observed by
scientific men, coincided with his doctrine.

Hence we may plainly see that Aristotle probably did not see
the incompatibility, supposed to be so glaring, upon which M.
Boeckh's argument is founded. To say the least, even if he saw it,
he did not consider it as glaring and decisive. He would have put
it in the foreground of his refutation, if he had detected the
gross contradiction upon which M. Boeckh insists. But Aristotle
does not stand alone in this dulness of vision. Among the various
commentators, ancient and modern, who follow him, discussing the
question now before us, not one takes notice of M. Boeckh's
argument. He himself certifies to us this fact, claiming the
argument as his own, and expressing his astonishment that all the
previous critics had passed it over, though employing other
reasons much weaker to prove the same point. We read in M.
Boeckh's second 'Commentatio de Platonico Systemate Coelestium
Globorum et de Vera Indole Astronomiae Philolaicae,' Heidelberg,
1810, p. 9, the following words:--

"Non moveri tellurem, Proclus et Simplicius ostendunt ex Phaedone.
Parum firmum tamen argumentum est ex Phaedone ductum ad
interpretandum Timaei locum: nec melius alterum, quod Locrus
Timaeus, quem Plato sequi putabatur, terram stare affirmat: quia,
ut nuper explicuimus, non Plato ex Locro, sed personatus Locrus ex
Platone, sua compilavit. At omnium firmissionum et certissimum
argumentum ex ipso nostro dialogo sumptum, _adhuc, quod jure
mirere, nemo reperit_. Etenim, quum, paulo supra, orbem
stellarum fixarum, quem Graeci [Greek: a)plane=] appellant,
dextrorsum ferri quotidiano motu Plato statuebat, non poterat
ullum terrae motum admittere; quia, _qui hunc admittit, illum non
tollere non potest_." (This passage appears again cited by M.
Boeckh himself in his more recent dissertation 'Untersuchungen
ueber das kosmische System des Platon,' p. 11). The writers named
(p. 7) as having discussed the question, omitting or disregarding
this most cogent argument, are names extending from Aristotle down
to Ruhnken and Ideler.

It is honourable to the penetration of M. Boeckh that he should
have pointed out, what so many previous critics had overlooked,
that these two opinions are scientifically incompatible. He
wonders, and there may be good ground for wondering, how it
happened that none of these previous writers were aware of the
incompatibility. But the fact that it did not occur to them, is
not the less certain, and is of the greatest moment in reference
to the question now under debate; for we are not now inquiring
what is or is not scientifically true or consistent, but what were
the opinions of Plato. M. Boeckh has called our attention to the
fact, that these two opinions are incompatible; but can we
safely assume that Plato must have perceived such incompatibility
between them? Surely not. The Pythagoreans of his day did not
perceive it; their cosmical system included both the revolution of
the earth and the revolution of the sidereal sphere round the
central fire, ten revolving bodies in all (Aristotel. Metaphysic.
i. 35, p. 96 a. 10. De Coelo, ii. 13, p. 293 b. 21). They were
not aware that the revolutions of the one annulled those of the
other as to effect, and that their system thus involved the two
contradictory articles, or "melange monstrueux," of which Martin
speaks so disdainfully. Nay, more, their opponent, Aristotle,
while producing other arguments against them, never points out the
contradiction. Since it did not occur to them, we can have no
greater difficulty in believing that neither did it occur to
Plato. Indeed, the wonder would rather be if Plato _had_ seen
an astronomical incompatibility which escaped the notice both of
Aristotle and of many subsequent writers who wrote at a time when
astronomical theories had been developed and compared with greater
fulness. Even Ideler, a good astronomer as well as a good scholar,
though he must surely have known that Plato asserted the rotation
of the sidereal sphere (for no man can read the 'Timaeus' without
knowing it), ascribed to him also the other doctrine inconsistent
with it, not noticing such inconsistency until M. Boeckh pointed
it out.

It appears to me, therefore, that M. Boeckh has not satisfactorily
made good his point--"Plato cannot have believed in the diurnal
rotation of the earth, because he unquestionably believed in the
rotation of the sidereal sphere as causing the succession of night
and day." For, though the two doctrines really are incompatible,
yet the critics antecedent to M. Boeckh took no notice of such
incompatibility. We cannot presume that Plato saw what Aristotle
and other authors, even many writing under a more highly developed
astronomy, did not see. We ought rather, I think, to presume the
contrary, unless Plato's words distinctly attest that he did see
farther than his successors.

Now let us examine what Plato's words do attest:--[Greek: ge=n de\
tropho\n me\n e(mete/ran, ei(llome/nen] (al. [Greek: ei(lome/nen,
i)llome/nen]) [Greek: de\ peri\ to\n dia\ panto\s po/lon
tetame/non phu/laka kai\ demiourgo\n nukto/s te kai\ e(me/ras
e)mechane/sato, pro/ten kai\ presbuta/ten theo=n, o(/soi e)nto\s
ou)ra/nou gego/nasi.]

I explain these words as follows:--

In the passage immediately preceding, Plato had described the
uniform and unchanging rotation of the outer sidereal sphere, or
Circle of The Same, and the erratic movements of the sun,
moon, and planets, in the interior Circles of the Diverse. He now
explains the situation and functions of the earth. Being the first
and most venerable of the intra-kosmic deities, the earth has the
most important place in the interior of the kosmos--the centre. It
is packed, fastened, or rolled, close round the axis which
traverses the entire kosmos; and its function is to watch over and
bring about the succession of night and day. _Plato conceives
the kosmic axis itself as a solid cylinder revolving or turning
round, and causing thereby the revolution of the circumference or
the sidereal sphere._ The outer circumference of the kosmos not
only revolves round its axis, but obeys a rotatory impulse
emanating from its axis, like the spinning of a teetotum or the
turning of a spindle. Plato in the Republic illustrates the
cosmical axis by comparison with a spindle turned by Necessity,
and describes it as causing by its own rotation the rotation of
all the heavenly bodies (Republ. x. p. 616, c. 617 A). [Greek: e)k
de\ to=n a)/kron tetame/non A)na/gkes a)/trakton, di' ou(= pa/sas
e)pistre/phesthai ta\s peri/phoras . . . , kuklei=sthai de\ de\
strepho/menon to\n a)/trakton o(/lon me\n te\n au)te\n phoran . .
. . stre/phesthai de\ au)to\n e)n toi=s A)na/gkes go/nasin.][1]

[Footnote 1: Proklus in his Commentary on the Platonic Timaeus (p.
682, Schn.) notes this passage of the Republic as the proper
comparison from which to interpret how Plato conceived the
cosmical axis. In many points he explains this correctly; but he
omits to remark that the axis is expressly described as revolving,
and as causing the revolution of the peripheral substance:--

----[Greek: to\n de\ a)/xona mi/an theo/teta sunagogo\n me\n to=n
ke/ntron tou= panto\s sunektike\n de\ tou= o(/lou ko/smou,
_kinetike\n de\ to=n thei/on periphoro=n_, peri\ e(\n e(
chorei/a** to=n o(/lon, peri\ e(\n ai(
a)nakukle/seis, a)ne/chousan to\n o(/lon ou)rano\n,**
e(\n kai\ A)/tlanta dia\ tou=to proseire/kasin, o(s
a)/trepton kai\ a)/truton e)ne/rgeian e)/chousan. kai\ me/ntoi
kai\ to\ tetame/non** e)ndei/knutai** tite/nion ei)=nai te\n
mi/an _tau/ten du/namin, te\n phrouretike\n te=s
a)nakukle/seos to=n o(/lon_.]

Here Proklus recognises the efficacy of the axis in producing and
maintaining the revolution of the Kosmos, but he does not remark
that it initiates this movement by revolving itself. The [Greek:
Theote\s], which Proklus ascribes to the axis, is invested in the
earth packed round it, by the Platonic Timaeus.]

Now the function which Plato ascribes to the earth in the passage
of the Timaeus before us is very analogous to that which in the
Republic he ascribes to Necessity--the active guardianship of the
axis of the kosmos and the maintenance of its regular rotation.
With a view to the exercise of this function, the earth is planted
in the centre of the axis, the very root of the kosmic soul
(Plato, Timaeus, p. 34 B). It is even "packed close round the
axis," in order to make sure that the axis shall not be displaced
from its proper situation and direction. The earth is thus not
merely active and influential, but is really the chief regulator
of the march of the kosmos, being the immediate neighbour and
auxiliary of the kosmic soul. Such a function is worthy of "the
first and eldest of intra-kosmic deities," as Plato calls the
earth. With perfect propriety he may say that the earth, in the
exercise of such a function, "is guardian and artificer of day and
night." This is noway inconsistent with that which he says in
another passage, that the revolutions of the outer sidereal sphere
determine day and night. For these revolutions of the outer
sidereal sphere depend upon the revolutions of the axis, which
latter is kept in uniform position and movement by the earth
grasping it round its centre and revolving with it. The earth does
not determine days and nights by means of its own rotations, but
by its continued influence upon the rotations of the kosmic axis,
and (through this latter) upon those of the outer sidereal sphere.

It is important to attend to the circumstance last mentioned, and
to understand in what sense Plato admitted a rotatory movement of
the earth. In my judgment, the conception respecting the earth and
its functions, as developed in the Platonic Timaeus, has not been
considered with all its points taken together. One point among
several, and that too the least important point, has been
discussed as if it were the whole, because it falls in with the
discussions of subsequent astronomy. Thus Plato admits the
rotation of the earth, but he does not admit it as producing any
effects, or as the primary function of the earth: it is only an
indirect consequence of the position which the earth occupies in
the discharge of its primary function--of keeping the cosmical
axis steady, and maintaining the uniformity of its rotations. If
the cosmical axis is to revolve, the earth, being closely packed
and fastened round it, must revolve along with it. If the earth
stood still, and resisted all rotation of its own, it would at the
same time arrest the rotations of the cosmical axis, and of course
those of the entire kosmos besides.

The above is the interpretation which I propose of the passage in
the Platonic Timaeus, and which I shall show to coincide with
Aristotle's comment upon it. Messrs. Boeckh and Martin interpret
differently. They do not advert to the sense in which Plato
conceives the axis of the kosmos--not as an imaginary line, but as
a solid revolving cylinder; and moreover they understand the
function assigned by the Platonic Timaeus to the earth in a way
which I cannot admit. They suppose that the function assigned to
the earth is not to keep up and regularize, but to withstand
and countervail, the rotation of the kosmos. M. Boeckh
comments upon Gruppe, who had said (after Ideler) that when the
earth is called [Greek: phu/laka _kai\ demiourgo\n_ nukto\s
kai\ e(me/ras], Plato must have meant to designate some active
function ascribed to it, and not any function merely passive or
negative. I agree with Gruppe in this remark, and I have
endeavoured to point out what this active function of the earth
is, in the Platonic theory. But M. Boeckh (Untersuchungen,
&c., p. 69-70) controverts Gruppe's remark, observing, first,
that it is enough if the earth is in any way necessary to the
production of the given effect; secondly, that if active force be
required, the earth (in the Platonic theory) does exercise such,
by its purely passive resistance, which is in itself an energetic
putting forth of power.

M. Boeckh's words are:--"Es kommt nur darauf an, dass er ein Werk,
eine Wirkung, hervorbringt oder zu einer Wirkung beitraegt, die
ohne ihn nicht waere: dann ist er durch seine Wirksamkeit ein
Werkmeister der Sache, sey es auch ohne active Thaetigkeit, durch
bloss passiven Widerstand, der auch eine maechtige Kraft-aeusserung
ist. Die Erde ist Werkmeisterin der Nacht und des Tages, wie
Martin (b. ii. p. 88) sehr treffend sagt 'par son energique
existence, c'est a dire, par son immobilite meme:' denn sie setzt
der taeglichen Bewegung des Himmels bestaendig eine gleiche Kraft in
entgegengesetzter Richtung entgegen. So _muss_ nach dem
Zusammenhange ausgelegt werden: so meint es Platon klar und ohne
Verhuellungen: denn wenige Zeilen vorher hat er gesagt, Nacht und
Tag, das heisst ein Sterntag oder Zeittag, sei ein Umlauf des
Kreises des Selbigen--_das ist, eine taegliche Umkreisung des
Himmels von Osten nach Westen, wodurch also die Erde in Stillstand
versetzt ist:_ und diese taegliche Bewegung des Himmels hat er
im vorhergehenden immer und immer gelehrt." . . . . "Indem Platon
die Erde nennt [Greek: ei(lome/nen], nicht [Greek: peri\ to\n
e(aute=s po/lon], sondern [Greek: peri\ to\n dia\ panto\s po/lon
tetame/non], setzt er also die taegliche Bewegung des Himmels
voraus" (p. 70-71).[2]

[Footnote 2: "We are only required to show, that the Earth
produces a work or an effect,--or contributes to an effect which
would not exist without such help: the Earth is then, through such
operation, an _Artificer_ of what is produced, even without
any positive activity, by its simply passive resistance, which
indeed is in itself a powerful exercise of force.**
The Earth is Artificer of night and day, according to the striking
expression of Martin, 'par son energique existence, c'est-a-dire,
par son immobilite meme:' for the Earth opposes, to the diurnal
movement of the Heavens, a constant and equal force in the opposite
direction. This explanation _must_ be the true one required
by the context: this is Plato's meaning, plainly and without
disguise: for he has said, a few lines before, that Night and Day
(that is, a sidereal day, or day of time) is a diurnal revolution
of the Heaven from East to West, whereby accordingly the Earth is
assumed as at rest: And this diurnal movement of the Heaven he has
taught over and over again in the preceding part of his
discourse."--"Since therefore Plato calls the Earth [Greek:
ei(lome/nen], not [Greek: peri\ to\n e(aute=s po/lon], but [Greek:
peri\ to\n dia\ panto\s po/lon tetame/non], he implies thereby the
diurnal movement of the Heaven."]

I not only admit but put it in the front of my own case, that
Plato in the Timaeus assumes the diurnal movement of the celestial
sphere; but I contend that he also assumes the diurnal rotation of
the earth. M. Boeckh founds his contrary interpretation upon the
unquestionable truth that these two assumptions are inconsistent;
and upon the inference that because the two cannot stand together
in fact, therefore they cannot have stood together in the mind of
Plato. In that inference I have already stated that I cannot
acquiesce.

But while M. Boeckh takes so much pains to vindicate Plato from
one contradiction, he unconsciously involves Plato in another
contradiction, for which, in my judgment, there is no foundation
whatever. M. Boeckh affirms that the function of the earth (in the
Platonic Timaeus) is to put forth a great force of passive
resistance--"to oppose constantly, against the diurnal movement of
the heavens, an equal force in an opposite direction." Is it not
plain, upon this supposition, that the kosmos would come to a
standstill, and that its rotation would cease altogether? As the
earth is packed close or fastened round the cosmical axis, so, if
the axis endeavours to revolve with a given force, and the earth
resists with equal force, the effect will be that the two forces
will destroy one another, and that neither the earth nor the axis
will move at all. There would be the same nullifying antagonism as
if,--reverting to the analogous case of the spindle and the
verticilli (already alluded to) in the tenth book of the
Republic,--as if, while Ananke turned the spindle with a given
force in one direction, Klotho (instead of lending assistance)
were to apply her hand to the outermost verticillus with equal
force of resistance in the opposite direction (see Reipubl. x. p.
617 D). It is plain that the spindle would never turn at all.

Here, then, is a grave contradiction attaching to the view of
Boeckh and Martin as to the function of the earth. They have not,
in my judgment, sufficiently investigated the manner in which
Plato represents to himself the cosmical axis: nor have they fully
appreciated what is affirmed or implied in the debated word
[Greek: ei(lo/menon--ei(lou/menon--i)llo/menon]. That word has
been explained partly by Ruhnken in his notes on Timaei Lexicon,
but still more by Buttmann in his Lexilogus, so accurately and
copiously as to leave nothing further wanting. I accept fully the
explanation given by Buttmann, and have followed it throughout
this article. After going over many other examples, Buttmann comes
to consider this passage of the Platonic Timaeus; and he explains
the word [Greek: ei(lome/nen] or [Greek: i)llo/menen] as
meaning--"_sich draengen oder gedraengt werden_ um die Axe: d. h.
von allen Seiten her an die Axe. Auch lasse man sich das Praesens
nicht irren: die Kraefte, welche den Weltbau machen und zusammen
halten, sind als fortdauernd thaetig gedacht. Die Erde draengt sich
(ununterbrochen) an den Pol, _macht, bildet eine Kugel um
ihn_. Welcher Gebrauch voellig entspricht dem wonach dasselbe
Verbum ein _einwickeln_, _einhuellen_, bedeutet. Auch
hier mengt sich in der Vorstellung einiges hinzu, was auf ein
_biegen_ _winden_, und mitunter auf ein _drehen_
fuehrt: was aber _ueberall nur ein durch die Sache selbst
hinzutretender Begriff ist_," p. 151. And again, p. 154, he
gives the result--that the word has only "die Bedeutung
_draengen_, _befestigen_, nebst den davon ausgehenden--die
von _drehen_, _winden_, aber ihm _gaenzlich
fremd_ sind, _und nur aus der Natur der Gegenstaende in
einigen Faellen als Nebengedanken hinzutreten_."[3]

[Footnote 3: "To _pack itself_, or to _be packed_, round
the axis: that is, upon the axis from all sides. We must not be
misled by the present tense: for the forces, which compose and
hold together the structure of the universe, are conceived as
continuously in active operation. The Earth _packs itself_,
or _is packed_, on to the axis--_makes or forms a ball
round the axis:_ which corresponds fully to that other usage of
the word, in the sense of _wrapping up_ or _swathing
round_. Here too there is a superadded something blended with
the idea, which conducts us to _turning_, _winding_, and
thus to _revolving_: but this is every where nothing more
than an accessory notion, suggested by the circumstances of the
case. The word has only the meaning, to _pack_, to
_fasten_--the senses, to _wind_, to _revolve_, are
altogether foreign to it, and can only be superadded as accessory
ideas, in certain particular instances, by the special nature of
the case."]

In these last words Buttmann has exactly distinguished the true,
constant, and essential meaning of the word, from the casual
accessories which become conjoined with it by the special
circumstances of some peculiar cases. The constant and true
meaning of the word is, _being packed or fastened close
round_, _squeezing or grasping around_. The idea of
_rotating_ or _revolving_ is quite foreign to this
meaning, but may nevertheless become conjoined with it, in certain
particular cases, by accidental circumstances.

Let us illustrate this. When I say that a body _A_ is
[Greek: ei(lo/menon] or [Greek: i)llo/menon] (packed or fastened
close round, squeezing or grasping around), another body _B_,
I affirm nothing about revolution or rotation. This is an idea
foreign to the proposition _per se_, yet capable of being
annexed or implicated with it under some accidental circumstances.
Whether in any particular case it be so implicated or not depends
on the question "What is the nature of the body _B_, round
which I affirm _A_ to be fastened?" 1. It may be an oak tree
or a pillar, firmly planted and stationary. 2. It may be some
other body, moving, but moving in a rectilinear direction. 3.
Lastly, it may be a body rotating or intended to rotate, like a
spindle, a spit, or the rolling cylinder of a machine. In the
first supposition, all motion is excluded: in the second,
rectilinear motion is implied, but rotatory motion is excluded: in
the third, rotatory motion is implied as a certain adjunct. The
body which is fastened round another, must share the motion or the
rest of that other. If the body _B_ is a revolving cylinder,
and if I affirm that _A_ is packed or fastened close round
it, I introduce the idea of rotation; though only as an accessory
and implied fact, in addition to that which the proposition
affirms. The body _A_, being fastened round the cylinder
_B_, must either revolve along with it and round it, or it
must arrest the rotation of _B_. If the one revolves, so must
the other; both must either revolve together, or stand still
together. This is a new fact, distinct from what is affirmed in
the proposition, yet implied in it or capable of being inferred
from it through induction and experience.

Here we see exactly the position of Plato in regard to the
rotation of the earth. He does not affirm it in express terms, but
he affirms what implies it. For when he says that the earth is
packed, or fastened close round the cosmical axis, he conveys to
us by implication the knowledge of another and distinct fact--that
the earth and the cosmical axis must either revolve together or
remain stationary together--that the earth must either revolve
along with the axis or arrest the revolutions of the axis. It is
manifest that Plato does not mean the revolutions of the axis of
the kosmos to be arrested: they are absolutely essential to the
scheme of the Timaeus--they are the grand motive-agency of the
kosmos. He must, therefore, mean to imply that the earth revolves
along with and around the cosmical axis. And thus the word [Greek:
ei(lo/menon] or [Greek: i)llo/menon], according to Buttmann's
doctrine, becomes accidentally conjoined, through the specialities
of this case, with an accessory idea of rotation or
revolution; though that idea is foreign to its constant and
natural meaning.

Now if we turn to Aristotle, we shall find that he understood the
word [Greek: ei(lo/menon] or [Greek: i)llo/menon], and the
proposition of Plato, exactly in this sense. Here I am compelled
to depart from Buttmann, who affirms (p. 152), with an expression
of astonishment, that Aristotle misunderstood the proposition of
Plato, and interpreted [Greek: ei(lo/menon] or [Greek:
i)llo/menon] as if it meant directly as well as incontestably,
_rotating_ or _revolving_. Proklus, in his Commentary on
the Timaeus, had before raised the same controversy with
Aristotle--[Greek: i)llome/nen de\, te\n sphiggome/nen deloi=
kai\ sunechome/nen ou) ga\r o(s A)ristote/les oi)/etai, te\n
kinoume/nen] (Procl. p. 681). Let us, therefore, examine the
passages of Aristotle out of which this difficulty arises.

The passages are two, both of them in the second book De Coelo;
one in cap. 13, the other in cap. 14 (p. 293 b. 30, 296 a. 25).

1. The first stands--[Greek: e)/nioi de\ kai\ keime/nen (te\n
ge=n) e)pi\ tou= ke/ntrou phasi\n au)te\n i)/llesthai peri\ to\n
dia\ panto\s tetame/non po/lon, o(/sper e)n to=| Timai/o|**
ge/graptai.** Such is the reading of Bekker in the Berlin edition:
but he gives various readings of two different MSS.--the one having
[Greek: i)/llesthai kai\ kinei=sthai]--the other ei(lei=sthai**
kai\ kinei=sthai].

2. The second stands, beginning chap. 14--[Greek: e(mei=s de\
le/gomen pro=ton po/teron] (the earth) [Greek: e)/chei ki/nesin
e)\ me/nei; katha/per ga\r ei)/pomen, oi( me\n au)te\n e(\n to=n
a)/stron poiou=sin, oi( d' e)pi\** tou= me/sou
the/ntes i)/llesthai kai\ kinei=shai/ phasi peri\ to\n po/lon me/son.]

Now, in the first of these two passages, where Aristotle simply
brings the doctrine to view without any comment, he expressly
refers to the Timaeus, and therefore quotes the expression of that
dialogue without any enlargement. He undoubtedly understands the
affirmation of Plato--that the earth was fastened round the
cosmical axis--as implying that it rotated along with the
rotations of that axis. Aristotle thus construes [Greek:
i)/llesthai], _in that particular proposition_ of the Timaeus,
as implying rotation. But he plainly did not construe [Greek:
i)/llesthai] as naturally and constantly either denoting or
implying rotation. This is proved by his language in the second
passage, where he reproduces the very same doctrine with a view to
discuss and confute it, and without special reference to the
Platonic Timaeus. Here we find that he is not satisfied to express
the doctrine by the single word [Greek: i)/llesthai]. He subjoins
another verb--[Greek: i)/llesthai kai\ kinei=sthai]: thus bringing
into explicit enunciation the fact of rotatory movement, which,
while [Greek: i)/llesthai] stood alone, was only known by
implication and inference from the circumstances of the
particular case. If he had supposed [Greek: i)/llesthai] by itself
to signify _revolving_ the addition of [Greek: kinei=sthai]
would have been useless, unmeaning, and even impertinent.
Aristotle, as Boeckh remarks, is not given to multiply words
unnecessarily.

It thus appears, when we examine the passages of Aristotle, that
he understood [Greek: i)/llesthai] quite in conformity with
Buttmann's explanation. Rotatory movement forms no part of the
meaning of the word; yet it may accidentally, in a particular
case, be implied as an adjunct of the meaning, by virtue of the
special circumstances of that case. Aristotle describes the
doctrine as held by _some persons_. He doubtless has in view
various Platonists of his time, who adopted and defended what had
been originally advanced by Plato in the Timaeus.

M. Boeckh, in a discussion of some length (Untersuch. p. 76-84),
maintains the opinion that the reading in the first passage of
Aristotle is incorrect; that the two words [Greek: i)/llesthai
kai\ kinei=sthai] ought to stand in the first as they do in the
second,--as he thinks that they stood in the copy of Simplikius:
that Aristotle only made reference to Plato with a view to the
peculiar word [Greek: i)/llesthai], and not to the general
doctrine of the rotation of the earth: that he comments upon this
doctrine as held by others, but not by Plato--who (according to
Boeckh) was known by everyone not to hold it. M. Boeckh gives this
only as a conjecture, and I cannot regard his arguments in support
of it as convincing. But even if he had convinced me that [Greek:
i)/llesthai kai\ kinei=sthai] were the true reading in the first
passage, as well as in the second, I should merely say that
Aristotle had not thought himself precluded by the reference to
the Timaeus from bringing out into explicit enunciation what the
Platonists whom he had in view knew to be implied and intended by
the passage. This indeed is a loose mode of citation, which I
shall not ascribe to Aristotle without good evidence. In the
present case such evidence appears to me wanting.[4]

[Footnote 4: Exactness of citation is not always to be relied on
among ancient commentators. Simplikius cites this very passage of
the Timaeus with more than one inaccuracy.--(ad Aristot. De Coelo,
fol. 125.)]

M. Martin attributes to Aristotle something more than improper
citation. He says (Etudes sur le Timee, vol. ii. p. 87), "Si
Aristote citait l'opinion de la rotation de la terre comme un
titre de gloire pour Platon, je dirais--il est probable que la
verite l'y a force. Mais Aristote, qui admettait l'immobilite
complete de la terre, attribue a Platon l'opinion contraire,
_pour se donner le plaisir de la refuter avec dedain_." A few
lines before, M. Martin had said that the arguments whereby
Aristotle combated this opinion ascribed to Plato were "very
feeble." I am at a loss to imagine in which of Aristotle's phrases
M. Martin finds any trace of disdain or contempt, either for the
doctrine or for those who held it. For my part, I find none. The
arguments of Aristotle against the doctrine, whatever be their
probative force, are delivered in that brief, calm, dry manner
which is usual with him, without a word of sentiment or rhetoric,
or anything [Greek: e)/xo tou= pra/gmatos]. Indeed, among all
philosophers who have written much, I know none who is less open
to the reproach of mingling personal sentiment with argumentative
debate than Aristotle. Plato indulges frequently in irony, or
sneering, or rhetorical invective; Aristotle very rarely.
Moreover, even apart from the question of contempt, the part which
M. Martin here assumes Aristotle to be playing, is among the
strangest anomalies in the history of philosophy. Aristotle holds,
and is anxious to demonstrate, the doctrine of the earth's
immobility; he knows (so we are required to believe) that Plato
not only holds the same doctrine, but has expressly affirmed it in
the Timaeus: he might have produced Plato as an authority in his
favour, and the passage of the Timaeus as an express declaration;
yet he prefers to pervert, knowingly and deliberately, the meaning
of this passage, and to cite Plato as a hostile instead of a
friendly authority--simply "to give himself the pleasure of
contemptuously refuting Plato's opinion!" But this is not all. M.
Martin tells us that the arguments which Aristotle produces
against the doctrine are, after all, very feeble. But he farther
tells us that there was one argument which might have been
produced, and which, if Aristotle had produced it, would have
convicted Plato of "an enormous contradiction" (p. 88) in
affirming that the earth revolved round the cosmical axis.
Aristotle might have said to Plato--"You have affirmed, and you
assume perpetually throughout the Timaeus, the diurnal revolution
of the outer sidereal sphere; you now assert the diurnal
revolution of the earth at the centre. Here is an enormous
contradiction; the two cannot stand together."--Yet Aristotle,
having this triumphant argument in his hands, says not a word
about it, but contents himself with various other arguments which
M. Martin pronounces to be very feeble.

Perhaps M. Martin might say--"The contradiction exists; but
Aristotle was not sharpsighted enough to perceive it; otherwise he
would have advanced it." I am quite of this opinion. If Aristotle
had perceived the contradiction, he would have brought it forward
as the strongest point in his controversy. His silence is to me a
proof that he did not perceive it. But this is a part of my case
against M. Martin. I believe that Plato admitted both the two
contradictory doctrines without perceiving the contradiction; and
it is a strong presumption in favour of this view that Aristotle
equally failed to perceive it--though in a case where, according
to M. Martin, he did not scruple to resort to dishonest artifice.

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 Timaeus (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 ete considere dans l'antiquite comme
partisan de l'immobilite absolue de la terre." M. Cousin had
before said, "Aristote se fonde sur ce passage pour etablir que
Platon a fait tourner la terre sur elle-meme: mais Aristote est,
dans l'antiquite, 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-meme." This is not strictly exact.
Aristotle understands the Platonic Timaeus 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 ou Platon parle de
l'equilibre de la terre, il ne dit pas un mot de sa rotation."

I know of only _one_ such passage--Phaedon, 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 Phaedon; 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 huitieme sphere, qui est Le Meme, devient nul par
rapport a elle, et les etoiles fixes, qui appartiennent a elle,
demeurent en apparence dans une immobilite absolue: ce qui est
contraire a _l'experience et au sens commun_, et a l'opinion
de Platon, exprimee dans ce meme 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 Timaeus, 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 Timaeus,
and ascribed to him by Aristotle (quite different from the
doctrine "que la terre tourne sur elle-meme"). 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: _draengt 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/nen] or [Greek: i)llome/nen] has no distinct
meaning at all, if it does not mean this. The very synonyms
([Greek: sphiggome/nen, peridedeme/nen], &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 spheres expliquent toutes les
apparences celestes; il n'y a donc aucune raison pour donner un
mouvement a 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 Timaeus 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 Timaeus, 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 Timaeus, 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 etoiles fixes, et deux
mouvemens aux planetes; puisqu'il ne range la terre ni avec les
unes ni avec les autres, il y a lieu de croire qu'elle ne
participe a 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 a ces raisons que Platon aurait necessairement
insiste sur le mouvement de la terre, s'il l'avait admis; et que
ce point etoit trop controverse de son temps et trop important en
lui-meme, pour qu'il ne fit que l'indiquer en se servant d'une
expression equivoque."

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 Lunae, 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 Meletus 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
Timaeus. And the second allegation I believe to be unfounded,
speaking with reference to the Platonic Timaeus. 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 Timaeus. 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 te=s sphai/ras
die=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
Phaedon as stationary in the centre of the heaven, we cannot
imagine Plato to affirm its rotation in the Timaeus. I agree with
M. Boeckh in thinking this argument inconclusive; all the more,
because, in the Phaedon, 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: te\n i)de/an te=s ge=s kai\
tou\s to/pous au)te=s**] (p. 108 E). No cosmical system or theory
is propounded in that dialogue.

When we turn to the Phaedrus, 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: no=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.[5] 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 Phaedrus,
are intended to be diurnal or not; I incline to believe not
([Greek: me/chri te=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 Phaedrus about the cosmical axis; and it is
upon this that the rotations of the earth intimated in the Timaeus
depend.

[Footnote 5: Whether [Greek: E)sti/a] in the Phaedrus, which is
said "to remain alone stationary in the house of the Gods," can be
held to mean the Earth, is considered by Proklus to be uncertain
(p. 681).]

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 Timaeus, 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 Phaedon, 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 Phaedon. Yet, though Gruppe is
aware of this important difference between the Republic and the
Phaedon, he still wishes to illustrate the Timaeus by the latter and
not by the former. He affirms that the earth in the Timaeus is
conceived as unattached, and freely suspended, the same as in the
Phaedon; but that in the Timaeus it is conceived, besides, as
revolving on its own axis, which we do not find in the Phaedon (p.
28, 29). Here I think Gruppe is mistaken. In construing the words
of Timaeus, [Greek: ei(lome/nen (i)llome/nen) 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/nen], 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/nen 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/nen] or [Greek:
i)llome/nen 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 Timaeus, I contend
that the authority of Aristotle contradicts instead of justifying
the conclusion at which he arrives. Aristotle understands [Greek:
i)llome/nen] 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 Timaeus (Plutarch. Quaest. 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] (Timaeus, 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\
_demiourgo\s_ nukto\s te kai\ e(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.

What has just been stated is, in my belief, the theory of the
Platonic Timaeus, signified in the words of that dialogue, and
embodied in the comment of Aristotle. The commentators, subsequent
to Aristotle, so far as we know them, understood the theory in a
sense different from what Plato intended. I think we may see how
this misconception arose. It arose from the great development and
elaboration of astronomical theory during the two or three
generations immediately succeeding Plato. Much was added by
Eudoxus and others, in their theory of concentric spheres: more
still by others of whom we read in Cicero (Academ. II. 39.)
"Hicetas Syracusius, ut ait Theophrastus, coelum, solem, lunam,
stellas, supera denique omnia, stare censet, neque praeter terram
rem ullam in mundo moveri: quae cum circum axem se summa
celeritate convertat et torqueat, eadem effici omnia, quae si
stante terra coelum moveretur. Atque hoc etiam Platonem in Timaeo
dicere quidam arbitrantur, sed paullo obscurius." The same
doctrine is said to have been held by Herakleides of Pontus, the
contemporary of Aristotle, and by others along with him.
(Simplikius ad Aristot. Physic. p. 64--De Coelo, p. 132--Plutarch.
Plac. Phil. III. 13.) The doctrine of the rotation of the Earth
here appears along with another doctrine--the immobility of the
sidereal sphere and of the celestial bodies. The two are presented
together, as correlative portions of one and the same astronomical
theory. There are no celestial revolutions, and therefore there is
no solid celestial axis. Moreover, even Aristarchus of Samos (who
attained to a theory substantially the same as the Copernican,
with the double movement of the Earth, rotation round its own
axis, and translation round the sun as a centre) comes within less
than a century after Plato's death.

Though the _quidam_ alluded to by Cicero looked upon the
obscure sentence in Plato's Timaeus as a dim indication of the
theory of Hicetas, yet the two agree only in the supposition of a
rotation of the earth, and differ essentially in the pervading
cosmical conceptions. Hicetas states distinctly that which his
theory denies, as well as that which it affirms. The negation of
the celestial rotations, is in his theory a point of capital and
coordinate importance, on which he contradicts both Plato and
Aristotle as well as the apparent evidence of sense. I cannot
suppose that this theory can have been proclaimed or known to
Aristotle when his works were composed: for the celestial
revolutions are the keystone of his system, and he could hardly
have abstained from combating a doctrine which denied them
altogether. In the hands of Hicetas (perhaps in those of
Herakleides, if we may believe what is said about him) astronomy
appears treated as a science by itself, with a view "to provide
such hypotheses as may save the phenomena" ([Greek: so/zein ta\
phaino/mena], Simpl. ad Aristot. De Coelo, p. 498, Schol.
Brandis). It becomes detached from those religious, ethical,
poetical, teleological, arithmetical decrees or fancies, in which
we see it immersed in the Platonic Timaeus, and even (though
somewhat less) in the Aristotelian Treatise De Coelo. Hence the
meaning of Plato, obscurely announced from the beginning, ceased
to be understood: the solid revolving axis of the Kosmos, assumed
without being expressly affirmed in his Timaeus, dropped out of
sight: the doctrine of the rotation of the earth was presented in
a new point of view, as a substitute for the celestial
revolutions. But no proper note was taken of this transition. The
doctrine of Plato was assumed to be the same as that of Hicetas.

When we read Plutarch's criticism (Quaest. Plat. p. 1006 C) upon
the word [Greek: i)llome/nen], we see that he puts to himself the
question thus--"Does Plato in the Timaeus conceive the earth as
kept together and stationary--or as turning round and revolving,
agreeably to the subsequent theory of Aristarchus and Seleukus?"
Here we find that Plutarch conceives the alternative thus--Either
the earth does not revolve at all, or it revolves as Aristarchus
understood it. One or other of these two positions must have been
laid down by Plato in the Timaeus.--So we read in Plutarch. But the
fact is, that Plato meant neither the one nor the other. The
rotation of the earth round the solid cosmical axis, which he
affirms in the Timaeus--is a phenomenon utterly different from
the rotation of the earth as a free body round the imaginary line
called its own axis, which was the doctrine of Aristarchus.

When expositors in Plutarch's day, and since his day, enquired
whether or not the Platonic Timaeus affirmed the rotation of the
earth, they meant to designate the rotation of the earth in the
sense of Aristarchus, and in the sense in which modern astronomy
understands that capital fact. Now speaking the language of modern
astronomy, I think it certain that the rotation of the earth is
_not_ to be found affirmed in the Platonic Timaeus; and I
agree with M. Boeckh when he says (Untersuch. p. 77), "Granting
that Aristotle ascribed to Plato the doctrine of the rotation of
the earth, he at least did not ascribe to him the doctrine as
Gruppe assumes, and as now understood." As between Gruppe--who
holds that the Platonic Timaeus affirms the rotation of the earth,
and that Aristotle ascribes it to him, in our sense of the
words--and M. Boeckh, who denies this--I stand with the latter for
the negative. But when M. Boeckh assumes that the only alternative
doctrine is the immobility of the earth, and tries to show that
this doctrine is proclaimed in the Platonic Timaeus--nay, that no
opposite doctrine _can_ be proclaimed, because the discourse
expressly announces the rotation of the sidereal heaven in
twenty-four hours--I am compelled to dissent from him as to the
conclusion, and to deny the cogency of his proof. M. Boeckh has
hardly asked himself the question, whether there was not some
other sense in which Plato might have affirmed it in the Timaeus. I
have endeavoured to show that there was another sense; that there
are good analogies in Plato to justify the belief that he intended
to affirm the doctrine in that other sense; and that the comments
of Aristotle--while thoroughly pertinent, if we thus understand
the passage in the Timaeus--become either irrelevant, dishonest, or
absurd, if we construe the passage as signifying either what is
maintained by M. Boeckh or what is maintained by Gruppe.

The eminent critics, whose opinions I here controvert, have been
apparently misled by the superior astronomical acquirements of the
present age, and have too hastily made the intellectual exigencies
of their own minds a standard for all other minds, in different
ages as well as in different states of cultivation. The question
before us is, not what doctrines are scientifically true or
scientifically compatible with each other, but what doctrines were
affirmed or implied by Plato. In interpreting him, we are required
to keep our minds independent of subsequent astronomical
theories. We must look, first and chiefly, to what is said by
Plato himself; next, if that be obscure, to the construction and
comments of his contemporaries so far as they are before us. In no
case is this more essential than in the doctrine of the rotation
of the earth, which in the modern mind has risen to its proper
rank in scientific importance, and has become connected with
collateral consequences and associations foreign to the ideas of
the ancient Pythagoreans, or Plato, or Aristotle. Unless we
disengage ourselves from these more recent associations, we cannot
properly understand the doctrine as it stands in the Platonic
Timaeus.

This doctrine, as I have endeavoured to explain it, leads to an
instructive contrast between the cosmical theories of Plato (in
the Timaeus) and Aristotle.

Plato conceives the kosmos as one animated and intelligent being
or god, composed of body and soul. Its body is moved and governed
by its soul, which is fixed or rooted in the centre, but stretches
to the circumference on all sides, as well as all round the
exterior. It has a perpetual movement of circular rotation in the
same unchanged place, which is the sort of movement most worthy of
a rational and intelligent being. The revolutions of the exterior
or sidereal sphere (Circle of the Same) depend on and are
determined by the revolutions of the solid cylinder or axis, which
traverses the kosmos in its whole diameter. Besides these, there
are various interior spheres or circles (Circles of the
Different), which rotate by distinct and variable impulses in a
direction opposite to the sidereal sphere. This latter is so much
more powerful than they, that it carries them all round with it;
yet they make good, to a certain extent, their own special
opposite movement, which causes their positions to be ever
changing, and the whole system to be complicated. But the grand
capital, uniform, overpowering, movement of the kosmos, consists
in the revolution of the solid axis, which determines that of the
exterior sidereal sphere. The impulse or stimulus to this movement
comes from the cosmical soul, which has its root in the centre.
Just at this point is situated the earth, "the oldest and most
venerable of intra-kosmic deities," packed round the centre of the
axis, and having for its function to guard and regulate those
revolutions of the axis, and through them those of the outer
sphere, on which the succession of day and night depends--as well
as to nurse mankind.

In all this we see that the ruling principle and force of the
kosmos ([Greek: to\ e(gemoniko\n tou= ko/smou]) is made to
dwell in and emanate from _its centre_.

When we come to Aristotle, we find that the ruling principle or
force of the kosmos is placed, not in its centre, but in its
circumference. He recognises no solid revolving axis traversing
the whole diameter of the kosmos The interior of the kosmos is
occupied by the four elements--earth, water, air, fire--neither of
which can revolve except by violence or under the pressure of
extraneous force. To each of them rectilinear motion is
_natural_; earth moves naturally towards the centre--fire
moves naturally towards the circumference, away from the centre.
But the peripheral substance of the kosmos is radically distinct
from the four elements: rotatory motion in a circle is
_natural_ to it, and is the only variety of motion natural to
it. That it is moved at all, it owes to a _primum movens
immobile_ impelling it: but the two are coeternal, and the
motion has neither beginning nor end. That when moved, its motion
is rotatory and not rectilinear, it owes to its own nature. It
rotates perpetually, through its own nature and inherent virtue,
not by constraining pressure communicated from a centre or from a
soul. If constraint were required--if there were any contrary
tendency to be overcome--the revolving periphery would become
fatigued, and would require periods of repose; but, since in
revolving it only obeys its own peculiar nature, it persists for
ever without knowing fatigue. This peripheral or fifth essence,
perpetually revolving, is the divine, venerable, and commanding
portion of the kosmos, more grand and honourable than the interior
parts or the centre. Aristotle lays this down (De Coelo, ii. 13,
p. 293, b. 10) in express antithesis to the Pythagoreans, who
(like Plato) considered the centre as the point of grandeur and
command, placing fire in the centre for that reason. The earth has
no positive cosmical function in Aristotle; it occupies the centre
because all its parts have a natural movement towards the centre:
and it is unmoved because there _must be_ something in the
centre which is always stationary, as a contrary or antithesis to
the fifth essence or peripheral substance of the kosmos, which is
in perpetual rotation by its own immutable nature.

I do not here go farther into the exposition of these ancient
cosmical theories. I have adverted to Aristotle's doctrine only so
far as was necessary to elucidate, by contrast, that which I
believe to be the meaning of the Platonic Timaeus about the
rotation of the earth.


LONDON: PRINTED BY W. CLOWES AND SONS, STAMFORD STREET,
AND CHARING CROSS.



****************************************************************
Transcriber's Note

The text is based on versions made available by the Internet Archive.

For the Greek transcriptions the following conventions have been used:
) is for smooth breathing; ( for hard; + for diaeresis; / for acute
accent; \ for grave; = for circumflex; | for iota subscript.
ch is used for chi, ph for phi, ps for psi, th for theta;
e for eta and o for omega; u is used for upsilon in all cases.

Corrections to the text, indicated with **

Text                         Correction
Ti/ma/io                     Ti/maio
chore/ia                     chorei/a
ou)/ranon                    ou)rano\n
tetamenon                    tetame/non
e)ndeiknutai                 e)ndei/knutai]
forge                        force
Tima/io|                     Timai/o|
gegraptai                    ge/graptai]
e(ilei=sthai                 ei(lei=sthai
e)/pi\                       e)pi\
a)ute=s                      au)te=s





End of the Project Gutenberg EBook of Plato's Doctrine respecting the
rotation of the Earth and Aristotle's Comment upon that Doctrine, by George Grote

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