[I.] Up to now [we have spoken] of the arguments which militate against the Earth’s diurnal motion alone, or against the diurnal and annual together; but henceforth [we treat] of those which, against the annual alone, could be devised either by others or by us. First there present themselves the arguments of the Peripatetics and of many others, derived from the nature of heavy and light bodies, and from that motion of theirs by which they require a right [proper] seat in the universe. These [arguments], in particular, Aristotle hurled against certain Pythagoreans (bk. 2 of the Heaven, chs. 12 & 13); [likewise] Ptolemy (bk. 1 of the Almagest, ch. 7); Alfraganus (difference 4); Cleomedes (bk. 1 of the Cyclic Theory, ch. 9); Albertus Magnus (bk. 2 On the Heaven and World, tr. 1, ch. 7, and On the Nature of Place, tr. 1, ch. 3); John of Sacrobosco (in the Sphere, ch. 1, and there Clavius, p. 135); Pierre d’Ailly (q. 3 on the Sphere); Maurolyco (Dialogue 1 of the Cosmography, p. 10); Barozzi (bk. 1 of the Cosmography, p. 35); Blancanus (in the Sphere, bk. 4, ch. 1); Scheiner (in the Mathematical Disquisitions, p. 35); Fortunio Liceti (in the disputations On the single center of motion); Giovanni Elefantuzio (On the structure of the whole orb); Scipione Chiaramonti (bk. 12 On the Universe, throughout); and — lest we neglect the Poets — George Buchanan (bk. 1 of the Sphere), where he first describes the opinion of the Pythagoreans who dwelt at Tarentum and Croton, and who said that Fire is in the middle of the universe, and that around it the Earth, with another opposite Earth, revolves — in these verses:

[Margin: Buchanan’s verses on the Situation of Fire and Earth in the Universe.]

Nor lighter was their error, in the placing of the earth and the wave — the error of those same Sages who inhabited the lofty walls of Croton, and Lacedaemonian Tarentum: since nature encloses in the whole body nothing purer or better than the living seed of flame, etc. To this, therefore, by far the most worthy seat seemed [to be] the secret inmost-chamber of the orb, and the middle recess, whence, from the sacred shrine, it might pour itself forth into all the parts — as (if it is right to compare great things with small) the HEART, the fount of blood and of life, which quickens the sluggish limbs in all living things, scatters from the cavern of the breast the vital heat through the other members. Next after the fire is the Earth situated by them; nor yet did they set this down as one [alone], but for this [Earth] too a Counter-earth, opposite, they made to roll eternal gyres around the fire.

Which premised, he at once rejects them, saying:

Perceive how far these things recede from the true reason: For, since for heavy bodies there is one force of moving of their own accord, so that they flee the convexities of heaven, and flow down into the middle center of the world — [it follows] that the Earth, lowest, settles of its own accord, and, by the middle station of the world, it must needs be that, balanced on the empty air, it shape itself into an orb.

[II.] These [arguments] are taken chiefly from Aristotle (bk. 2 On the Heaven, chs. 12 & 13), as we shall soon see. Now Aristotle’s arguments — because they are lightly touched by some, and by certain [authors] even adduced with too little fidelity, or weakened — their force is not to be dissembled by us, but to be exerted whole, as great as it is; nor is the text either of itself always so clear, or so clearly translated from Greek into the Latin tongue, that it may not seem to some [to be] obscure. It will be worth the trouble to transcribe here his select texts which bear on this matter, with a very brief paraphrase where there is need, that from them we may draw out the thread of the Peripatetic doctrine, and the force of the arguments, as a kernel from the husk.

[Margin: Aristotle’s select texts bearing on this controversy. — On the Heaven, bk. 2, text 72.]

And so Aristotle (bk. 2 On the Heaven, ch. 12, text 72) proposes the questions to be treated in that and the following chapters, saying: It remains to speak of the Earth — where it is placed, and whether it is among those [things] which are at rest or among those which are moved, and concerning its figure. And a little later he says: Since most [people], who say that the whole heaven is finite, place [the Earth] lying in the middle, those who dwell about Italy — and are called Pythagoreans — say the contrary: for they say that in the middle is Fire; and that the Earth is one of the stars, and, carried in a circle around the middle, makes night and day. That is, [they hold] that it is so carried, by the annual motion, around the center of the universe, that nevertheless it also, by the diurnal whirling, makes the vicissitudes of night and day. He continues in the same text, and relates of the same [Pythagoreans]:

[Margin: Text 73.]

Moreover, they fashion another earth, opposite to this one, which they call by the name Counter-earth [Antichthon] — not seeking the cause from those [things] which appear to sense, but rather striving to drag the appearances over to certain opinions and reasonings of their own, and attempting to dress these up — that is, with the colors of certain plausibilities. For he subjoins (text 73), as if divining the things which were later to be fashioned by the Copernicans: To many others, too, it will seem that one ought not to assign the middle to the Earth — taking their argument not from the things which appear, but rather from reasonings. For they think that to the most honorable [thing] the most honorable region is owed; and that Fire is more honorable than Earth, and that the Boundary [belongs] to the intermediate parts, and that the Extreme and the center have the character of a Boundary. Wherefore, reasoning from this, they judge that the Earth is not situated in the middle of the sphere, but rather the Fire. Moreover, the Pythagoreans add this reason too: that it is most fitting that that which is the most principal [thing] of the universe be preserved [guarded]; and that the middle of the world is most apt for that — which accordingly they name the Prison of Jupiter — and therefore that this region befits the Fire.

But the Copernicans understood, for this most honorable and most principal Fire, the Sun itself. And at once the Philosopher, in text 74, twice carps at the Pythagoreans and the rest [who] thus hold: First, that they use an equivocation, and confound the middle of magnitude (such as is the center of the sphere and of the world) with the middle of the thing and of nature, which is not always the same, as is clear in animals; for the middle of the animal and the middle of the body are not the same in them. For whether the brain is the chief part of the animal (in which the soul exercises the common sensations), or the heart (in which is the principle of the vital operations), neither is at the middle of the bodily magnitude, or of the organic body; and in us, indeed, the heart is much nearer to the head than to the feet — which example Aristotle does not express, but it is enough for him to have indicated this. Secondly, between the two extremes of the sphere — namely the center and the surface — he says that the surface is more honorable, because this has the character of an end and of a container, while that [the center has the character] of [something] finite, or bounded and contained by another. Which explanation premised, you will better understand the words of text 74, which are as follows:

[Margin: Text 74.]

As though the middle were [meant] simply — that is, said in one single way — and the middle of magnitude were the same as the middle of the thing and of nature; whereas, just as in living creatures the middle of the animal and [the middle] of the body are not the same, so, and much more, must it be judged concerning the whole heaven and world. For this cause, therefore, it was not fitting that they be disturbed about the places of the universe, nor bring that guard — namely of Jupiter — to the center, but [rather] to seek what kind of thing the middle of the thing is, and where by its nature it is apt to be. For a middle of this kind is a principle, and more honorable. But the middle of place is likened to the extreme rather than to the principle; for the middle of place is that which is determined [bounded], and that which determines is an end; and the end and container is more honorable than the finite [bounded]; for this [the bounded] is matter, but that [the end] is the substance of the constitution itself.

And after these things, in text 75, he hints at the opinion…

[…continues on p. 440 (PDF 475) with the catchword “nio-” (opi-nio-nem) — Aristotle’s text 75, hinting at the opinion [of those who place the Earth elsewhere than the center], the next of the select texts.]

(printed p. 440 — within Chapter XXV: Riccioli’s running transcription of Aristotle’s De Caelo II.13 continues — the remaining ancient opinions on the Earth’s place and rest (Xenophanes, Thales, Anaximenes, Empedocles, Anaximander) with Aristotle’s counters, then Aristotle’s own arguments that a moving Earth’s motion would be violent and that heavy bodies fall to the universe’s middle (where Galileo and Kepler note he assumes what is in question), concluding that the Earth is necessarily central and immovable.)

[Header: BOOK IX. SECTION IV.]

[Margin: Text 75.]

…[he hints at the opi]nions of certain [men] about the motion of the earth; and among other things, those words are worthy of note: Whoever indeed deny that the earth is situated in the middle say that it is moved circularly around the middle — and not only this [earth], but the Counter-earth too. And a little later he says that some, from the fact that to us — observing the celestial phenomena from the earth’s surface — no notable difference appears (although we are distant from the Earth’s center by a whole semidiameter), reckoned that all things could appear to us just the same whether the Earth be in the middle of the Universe or not. For this is the sense of those words: Since the Earth is not the center, but is distant from the center by its whole [hemisphere’s] semidiameter, they think nothing hinders the Phenomena from happening in the same way if we did not dwell at the center of the world, as [they would] if the Earth were at the middle of the world; for nothing notable now happens to us, [we being] distant from the center by half a diameter.

He finally closes text 75 by relating the opinion of Plato (or of the Timaeus), about the Earth at the center of the world but rolled round by a whirling about its own center and an unmoved axis: But some say that it [the Earth], even lying at the center, is turned, and moved about the ever-unmoved pole, as is written in the Timaeus — that is, about the pole of the axis of the terrestrial Equator. Further (text 76) he proposes opinions about the figure of the Earth; and (text 77) he brings forward a most weighty question, worthy of our understanding, saying:

[Margin: Texts 76 & 77.]

For perhaps it would be [the mark] of a rather irrational mind not to wonder how it is that a small particle of earth, if raised up and let go, is borne downward and will not rest (and the greater part is always borne more swiftly), yet the whole earth, if one should imagine it raised up and then let go, would not be borne downward, but, being of so great a gravity as it is, would rest? Again, if someone, having taken its particles before they fall, were to take away the whole earth, those [particles] would nevertheless be borne downward, nothing resisting.

He says (text 78) that from these doubts various solutions arose: that Xenophanes of Colophon indeed said the whole Earth is not borne downward because it has an infinite root below, by which it is sustained; but that Thales of Miletus said it floats on the waters — whom he carps at (text 79), as though the water itself did not also need some [other] body to sustain it, and as though the whole earth, being heavier, ought not to descend through the water (since any part of the earth, let go, descends through water).

[Margin: Text 80. Aristotle’s admonition on philosophizing rightly.]

Whence (text 80) he observes that some philosophize only so far as to satisfy themselves, and to acquiesce in the reasons first occurring, so long as they have nothing to say against them. But he warns that one philosophizing rightly ought to be otherwise disposed, subjoining that golden admonition: Wherefore, in order to inquire well, one must be fit to raise objections through the objections proper to each genus; and this arises from having contemplated all the differences.

[Margin: Texts 81, 82, etc. — From texts 86 to 89.]

Soon (text 81) he relates the opinion of Anaximenes, Anaxagoras, and Democritus, who attributed a broad [flat] figure to the Earth, so that it could not be borne downward; whom he attacks from text 82 to 85. In which text he relates Empedocles saying that the Earth is not borne downward because it is prevented by the most rapid conversion of the heaven — just as water in a bowl swiftly whirled round cannot fall up or down. Against whom he urges many [objections] from text 86 to 89; where this is to be noted: But is the heavy and the light determined even by the whirling? Rather, the heavy and light existing first, the former come to the middle, while the latter rise above [it], on account of the motion.

[Margin: Text 90.]

Next (text 90) he relates the opinion of Anaximander, saying that the whole Earth is not moved, because, since it is in the middle, there is no reason why it should be borne more into one part than another — in that all the regions of the world are, for the whole earth, under one account downward, under another upward, and so none is more upward than downward.

[Margin: Text 91.]

Which (text 91) he says is wittily, but not truly, said; otherwise whatever body were once placed at the middle of the world — whether earth, fire, air, or water — would there rest perpetually; for the reason adduced by Anaximander is not proper to the Earth itself. And besides, the reason ought to have been rendered why the parts of the earth are borne to the middle. Therefore (text 92) he says:

[Margin: Text 92.]

For it seems not only to remain at the middle, but also to be borne to the middle; for whither any particle of it is borne, thither the whole too must necessarily be borne; and where anything is borne according to nature, there too it must necessarily remain according to nature.

[Margin: Text 93.]

Besides this (text 93) he says it is absurd to ask why the Earth remains at the middle, and not to ask why fire remains at the extreme; for if to those [light bodies] by their nature the extreme place befits, it is manifestly necessary that to the Earth too some place should befit by nature. The rest, with which he acutely presses Anaximander, may be read in texts 94 & 95, by which chapter 12 is concluded.

[Margin: ¶III — On the Heaven, text 96.]

[III.] But in chapter 13, Aristotle (texts 96 & 97) first determines whether the Earth is moved, and tries to show that it is not moved — in the prior text 96 from the nature of the whole Earth, which however he investigates from the motion of the [earth’s] parts. And so he begins thus (text 96): But let us first say whether it has motion or remains [at rest]. For, as we said, some make it one of the stars; others, placing it in the middle, say that it is turned and moved about its own middle and pole. But that this is impossible we shall try to make manifest, making a beginning from this first argument: that if the earth — whether existing in the middle or outside the middle — is moved, it is necessary that it be moved violently by a motion of this kind; for [such a motion] does not befit the earth itself by nature, otherwise each one of [its] particles would have this carrying; but now all are borne in a straight line to the middle. Accordingly, since this motion is violent and beside nature, it is not possible that it be everlasting; but the order of the World is everlasting.

[Margin: Text 97.]

Afterward (text 97) he subjoins an argument a posteriori, from the twofold motion of the Planets — which, he says, ought to befit the Earth too, if it were moved — and yet that [twofold motion] cannot be in the Earth while the phenomena are saved; but this argument pertains to chapter 26.

[Margin: Text 98.]

He proceeds next to other arguments from the motion of heavy bodies to the center of the Universe, and (text 98) says: Moreover, the carrying of the parts, and of the whole itself, according to nature, is to the middle of the universe; for this reason it [the earth] is placed, and exists even now, at its [the universe’s] center. Which, in order to prove, needed the solution of two questions: the first, whether heavy bodies are borne to the center of the Earth; the other, whether they are borne to the center of the Earth qua center of the Earth, or qua it is the same in subject and in reality with the center of the Universe. This latter he solves first, saying (text 99):

[Margin: Text 99.]

But someone might doubt: since the middle of both is the same, to which [center] are [things] which have gravity, and the parts of the earth, borne according to nature — to the center (or middle) of the Earth, as it is the middle of the Earth, or as it is the middle of the Universe? Accordingly I say it is necessary that they be borne to that which is the middle of the Universe; for fire and all light things whatever, which are borne into the parts contrary to those toward which heavy things tend, are borne to the middle of the place of the outermost container — that is, toward the supreme surface of the heaven, which is the universal place — but it happens that the same is the middle of the Earth and of the universe at once; for they are borne also to the Earth’s middle, but according to accident, inasmuch as it [the Earth] has its own middle at the middle of the Universe.

By which two texts, indeed, it seemed to Galileo and Kepler that Aristotle assumed what is in question — namely that the center of the Earth and of the universe is the same; concerning which [more] afterward. Meanwhile the Philosopher easily solves the second question (text 100), saying:

[Margin: Text 100.]

But that they are borne also to the Earth’s middle, the sign is that weights carried to this [earth] are borne along lines not equidistant [parallel], but at similar angles; wherefore all are borne to one middle, which indeed is the middle of the Earth.

Or, as Ptolemy discusses (bk. 1, ch. 7), all weights fall perpendicularly onto the Earth’s surface, and everywhere make right angles on both sides with the Tangent to the Earth’s globe at the point above which they are let go; whence it comes about that the lines of all plumb-lines, and of walls erected to the perpendicular, meet at the center of the Earth. From what was now said in texts 98, 99, and 100, Aristotle concludes (text 101) thus:

[Margin: Text 101.]

It is manifest, therefore, that the Earth must necessarily be situated at the middle of the Universe, and immovable.

But because someone could object that, from the said propositions (if conceded), it follows only that the earth is not moved by the motion of translation [revolution], but not that it is not moved by the motion of whirling about the unmoved center of itself and of the universe — he subjoins, in the same text 101: And on account of the said causes, and because weights which are violently thrown upward are borne back to the perpendicular into the same [spot], even if that force should throw [them] to infinity. That [the earth], therefore, neither moves nor lies outside the middle, is manifest from these things. Hence, a regress being made, from the natural rest of the earth he gathers that the motion of heavy bodies and of the parts of the Earth, receding from the middle, is violent; and thence concludes that much more is the motion of the whole earth, receding from the middle, violent. And so (text 102) he discusses thus:

[Margin: Text 102.]

Besides this, the cause of [the earth’s] rest is manifest from what has been said. For if the ear[th]…

[…continues on p. 441 (PDF 476) with the catchword “si tel-” (si tel-lus) — “…if the earth, by its own nature, is born to be carried on all sides to the middle,” completing Aristotle’s text 102.]

(printed p. 441 — within Chapter XXV: Aristotle’s De Caelo II.13 is finished (no particle, hence not the whole Earth, naturally recedes from the middle), and Riccioli begins an epitome of De Caelo Book 4 on gravity and levity — the definitions of up and down, simply and comparatively heavy and light, the critiques of the Platonists and the atomists, and the axiom that each body is carried to its own place qua place, with the thought-experiment that an Earth set at the Moon’s place would not draw falling bodies to itself.)

[Header: DE SYSTEMATE TERRÆ MOTÆ — 441]

…if the earth, by its own nature, is born to be carried on all sides to the middle, just as fire too seems [to be carried] from the middle to the extreme — that is, to be carried by its own nature: It is impossible that the motion of any particle of it, by which it recedes from the middle, not be violent; for there is one carrying of one [thing], and it is simple for a simple body, and not contrary [to itself] — that is, to one simple body, of which kind is the Earth, two contrary carryings do not naturally belong; and that which is from the middle is contrary to that which is to the middle. Therefore, if it is impossible for any particle of earth to recede from the middle — understand: naturally — it is manifest that it is still impossible for the whole Earth too to recede from the middle of the universe; for to that toward which the part is born to be carried, the whole too is born to be carried thither. Wherefore, if it is impossible for it to be moved except by a stronger power, it is necessarily [fixed] at the very middle.

[Margin: Text 103.]

Finally (text 103) he confirms this situation of the Earth by another argument, from the celestial Phenomena, which happen as if the Earth were in the middle; but these, like text 97, pertain to the arguments to be proposed in chapter 26. And he concludes chapter 13 with his usual recapitulation: Concerning [its] place, then, and rest and motion, how they stand — so much has been said about the Earth itself. For in chapter 14 he treats of the Figure of the Earth; which finished, he finishes book 2 On the Heaven. But in book 3 he treats of the Generation, number, and difference of the Elements; and in book 4 he treats of Gravity and Levity, and which [qualities], and in what degree, belong to the individual elements. This doctrine, because it is very useful for better understanding Aristotle’s arguments for the Earth’s place, will be reduced by us into a very brief compendium, those things being selected which are most pertinent here.

[Sub-head:] Selected [Texts], as if into an Epitome, from Book 4 On the Heaven.

[Margin: Texts 1 & 2.]

[IV.] And so, in text 1 of book 4 On the Heaven, he says he will treat of the Heavy and the Light — what each is, what their nature is, and why they have these powers; and in text 2 he supposes that the Heavy and Light can in some way be moved naturally, but observes that no name has been imposed on their act, unless one think that propensity or inclination to motion is a name suiting it; and that Heavy and Light bodies have in themselves, as it were, incitements to motion; and that all authors use their powers (namely gravity and levity), yet few have determined about them.

[Margin: Text 3.]

And (text 3) that the Ancients discussed only that which is lighter or heavier than another (as bronze [is heavier] than wood) — that is, the light and heavy comparatively — but not that which is simply and absolutely heavy or light.

[Margin: Text 4. The difference of up and down established.]

Now let the words of text 4 be noted: For these — that is, the Light — are always born to be carried from the middle; but those always to the middle — that is, the Heavy. And of these, that which is carried from the middle we say is carried upward; but downward, that which [is carried] to the middle. For it is absurd not to judge that in the heaven — that is, in the World, which he often names thus from its better part — there is something which is upward, and another which is downward; as some think. For they say that there is not one [thing] up and another down, if [the world] is similar in every part, and anyone can walk all around with his feet opposite to himself [i.e. the Antipodes]. — Thus thought Timaeus, as Simplicius reports on this text. — But we say that the extreme of the Universe itself is upward, which is both upward according to position, and first by nature.

[Margin: Text 5, illustrated.]

But in text 5, from the fact that the heaven has not only an extreme but also a middle, he concludes that there is an up and a down — provided the heaven be everywhere spherical; otherwise, if only a single hemisphere were given, that which will be the middle in it will not have the character of the [proper] “down”; for then one of the extremes will be the earth itself, and the middle will be something between heaven and earth — and so it would not suffice to establish the difference of the downward situation, [namely] the account of the middle in the universe, unless the universe be spherical. By which paraphrase you will now understand this text (otherwise obscure to many), which is such: Since something of the heaven itself is the extreme and the middle, it is plain that there will be both an up and a down, as many also say — but not sufficiently. The cause of this is that they think the heaven is not everywhere similar, but [think] there is only a single hemisphere, which is above us. But those who reckon that it is such all around, and that the middle similarly behaves toward the universe, this indeed they will say is upward, but the middle downward. — So far, then, is it [from the truth] that, from the fact that the earth can be walked all around, and the feet can stand in a region opposite to themselves at different times (or that anyone can become his own Antipodes), the position of up and down should be abolished, that rather it is hereby established by Aristotle. Which established, he repeats (text 6) his definition or description, saying:

[Margin: Text 6.]

Simply Light, then, we call that which is carried upward, and to the extreme; but simply Heavy, that which [is carried] downward and to the middle. But Light relatively [to another], or Lighter, [is] that which, between two [bodies] equal in bulk, is by nature carried upward more swiftly than the other.

— Where the corrupted texts have “down” instead of “up.”

[Margin: Text 8.]

These determined, in texts 8 and 9 he presses the Platonists, who in the Timaeus defined the Heavier to be that which consists of more [parts] of the same [kind], and the Lighter that which [consists] of fewer — just as a larger lead is heavier than a smaller, and bronze than bronze, and likewise of two other individuals of the same species; in which matter they would not have erred, had they defined only that which is heavier in an individual [comparatively]. But in this way, he says, the heavy and light taken simply are not determined. He subjoins: But in the same way they say that lead is heavier than wood —

[Margin: Text 9.]

— which he teaches (text 9) to be absurd: both because fire would be sometimes lighter, sometimes heavier, according as it consisted of more or fewer parts, and thus the simply Light would be abolished; and because a larger fire, being heavier, would be carried upward more slowly than a smaller — yet Fire is always light, and simply light, and the larger it is, the more swiftly it is carried upward.

[Margin: Text 10.]

But that he denies (text 10) the light to be that which consists of fewer, the heavier that which consists of more triangles — he alludes to Plato in the Timaeus, who attributes to Earth the Cube, to Water the Icosahedron, to Air the Octahedron, to Fire the Pyramid [tetrahedron], as Simplicius notes there.

[Margin: Text 11.]

Now in text 11 he reproves those who defined the Heavier from a multitude of planes or from greater bulk, as though bulks consisted of indivisible planes. But many things are heavier than others which yet are smaller in bulk, as bronze [is heavier] than wool.

[Margin: Texts 12 to 20.]

But because Leucippus and Democritus (as Simplicius reports here, comment 4) referred the cause of gravity to the solidity of atoms, and of levity to the interposition of void — he harasses them, from text 12 to 20, with many objections; but this is the principal one: that gold and earth could be given containing more void within themselves than some fire, and yet would not turn out lighter; and that the void is not moved, nor needs a place upward, since it is rather itself a place (if it be admitted to be given).

[Margin: Text 22.]

But in text 22 he assumes as an axiom that each of the natural bodies is naturally carried to its own place, and flees from the contrary place, inasmuch as [the place] is such [its proper place]: for just as in other changes a transit is made from one to the other contrary [which is] intended per se — as in Generation to form, in alteration to quality, in augmentation to quantity of substance — so in natural carrying it must be that the movable tends to its place, inasmuch as it is its own place. Wherefore he reproves some of the Ancients who said that Heavy and Light bodies are carried downward and upward because they are carried to what is similar to themselves; for although it is true that in the place to which they are carried there are things of similar nature (in the place to which earthy things are carried there is earth, and to which airy things there is air), nevertheless that which is the formal terminus of the local motion of Heavy and Light bodies is the place, inasmuch as such a place in the universe is suitable to them; which he confirms thus:

[Margin: Text 23.]

For if one should transpose the Earth to where the Moon now is, each of [its] parts would not be carried to it [the Earth], but to that place where it now also exists.

— Let the Copernicans note this, who say that heavy and light bodies are carried to their wholes not by reason of place, but on account of kinship in nature. Yet Aristotle concedes (text 23) that the intermediate elements are also carried, by another reason, toward what is similar to themselves — for water is similar to air, and air to fire; but this he denies of the extreme elements. And (text 24) he again teaches that this similarity is not the formal terminus of the local motion of heavy and light bodies, but the place itself, up and down, inasmuch as it is such; just as that which is curable, if it be changed qua curable, is moved to health, not to whiteness — even if whiteness were found conjoined with health.

[Margin: Text 24.]

But to ask, says the Philosopher, for what reason fire is carried upward, and earth downward, is the same as [to ask] for what reason the curable, if it be moved and changed inasmuch as it is curable, tends to health, and not to whiteness.

[…continues on p. 442 (PDF 477) with the catchword “mat” (confir-mat) — “Which doctrine he confirms…,” carrying on the epitome of De Caelo Book 4.]

(printed p. 442 — within Chapter XXV: the De Caelo Book-4 epitome concludes (relative gravity and levity, media, and figures). Then the First Argument for the Earth’s place at the center of the Universe is framed at full strength: the terminus toward which all heavy bodies naturally tend per se is the Earth’s center, and that terminus is the center of the Universe — the Major proved from converging fall-lines, the Minor by an exclusive and an inclusive proof.)

[Header: BOOK IX. SECTION IV.]

[Margin: Text 25.]

…[he confir]ms [it] in text 25, because when air comes to be from water, three changes intervene: a Generation terminated at the substantial form; an alteration to the qualities; and immediately a carrying to a place higher than the water. Granted, then, that air is more similar to air than water is, nevertheless it is not for that reason carried to the air-region — because it is [made] similar; for this similarity consists in the quality which it has now acquired by the force of alteration. Therefore it ascends upward to such a place, inasmuch as this place is owed to the lighter [body]. He concludes, then, that each of these is carried to its own place, inasmuch as such a place is owed to them in the universe.

These subtly disputed, in texts 26 and 27 he defines the Heavy and Light, both simply and relatively [secundum quid], by this new formula:

[Margin: Texts 26 & 27.]

First, indeed, it is defined as it seems to all: the simply Heavy is that which subsides beneath all; but the Light, that which rises above all. And (text 27): But [there is] the relative heavy and light, in which both are present; for they rise above and subside beneath certain [things], as air and water; for neither of these is simply light or heavy, etc.

[Margin: Texts 28 & 29.]

And (text 28) he teaches that the cause of gravity and levity in compounds (or mixed [bodies]) is the greater or lesser participation in the qualities and differences of the elements. And at once (text 29) he brings forth his opinion about [things] participating in gravity, in these words: It happens, then, that the same things are not everywhere seen [to be] heavy and light, because of the difference of the primary [bodies]: for example, in air, wood of one talent will be heavier than lead of one pound, but in water lighter; and the cause is that all things have gravity except fire, and all [have] levity except earth, etc.

[Margin: Text 30.]

And (text 30): For in its own region everything has gravity except fire — even the air itself: of which the sign is that an inflated [wine-]skin draws more — namely, [pulls] downward the scale-pan or the hand sustaining it — than an empty one. And he concludes this text thus: Wherefore, if anything has more of air than of earth and water, in water indeed it happens to be lighter, but in air heavier; for to the air it does not rise above, but to the water it does rise above.

[Margin: Text 31.]

There follows text 31, in which, defining again, he says: But I call simply light that which is always born to be carried upward [when] not prevented, and heavy that which [is always born to be carried] downward. And he affirms that there are certain things which are simply light and have no gravity (against some who say all things have something of gravity);

[Margin: Text 32.]

and he proves this (text 32) from the fact that fire rises above all, and subsides beneath none of the elementary bodies — but it would subside, he says, if it had any gravity. (The adversaries, however, would say that it subsides beneath none because all things are heavier than fire.)

[Margin: Text 33.]

And (text 33) he confirms that there is a middle in the Universe, to which heavy bodies, and from which light bodies, are carried, because there is no motion downward to infinity; and he subjoins this confirmation: Next, fire seems to be carried upward at similar angles, but earth and everything which has gravity, downward. Wherefore it must necessarily be carried to the middle. But whether this happens, per accidens, to the middle of the Earth or to [that] of the Universe — since their center is the same — is another discourse.

[Margin: Text 34.]

But Aristotle pursues it, and proves the same proposition (that there is a Heavy and Light simply) from text 34, by two most congruent reasons: for if there is given both that which subsides beneath all and that which rises above all, and there is given a middle and an extreme in the universe to which certain bodies are carried simply — are not the Heavy and Light simply reasonably granted? I now pass over the following texts, because they do not make much for our matter, and come to text 39, in which I should wish these propositions, above the rest, noted:

[Margin: Text 39.]

If it [a body] be taken away [from below], it is carried into that which is next [below]: air indeed into the region of water, water into that which is earth; but upward, into the region which is fire’s, the fire being taken away, air will not be carried, except by force — just as water is drawn upward by a contiguous higher surface, if one draw upward more swiftly than the water is carried downward; nor [is] water [carried] into that which is air’s, except by force. And a little later: But just as neither is earth [carried] upward, so neither is fire carried downward when the air is taken away — understand: except by force, by something drawing [it] to fill a vacuum — for [fire] has no gravity in its own region, nor earth levity.

Texts 40 and 41 do not make for our matter; nor [do] the remaining four (that is, 42, 43, 44, and 45), in which last [texts], however, he teaches that the figures of bodies do not produce the Heavy and Light, and so are not motive downward or upward; but, motion being presupposed [as coming] from Gravity or Levity, that the figures contribute to a greater or lesser velocity.

[Header (right column): BOOK IX. SECTION IV.]

These [things] premised, we must proceed to the arguments.

I. Argument for the Earth’s place at the center of the Universe

[V.] There is the center of the Earth where there is the terminus toward which all Heavy bodies naturally tend per se; but a terminus of this kind is the center of the Universe. Therefore the Earth is at the center of the Universe.

The Major is proved, because, on the one hand, the center of the Earth is there where there is the terminus toward which all Heavy bodies are carried — since, let go on all sides and from any place whatever, they are carried along straight lines not equidistant [parallel] among themselves, but meeting at one point, and so falling perpendicularly upon the convex surface of the Terraqueous globe (or making, with the straight line tangent to the terrestrial globe, right angles on both sides at the point of contact); and this happens everywhere on earth. And accordingly Aristotle (2nd On the Heaven, text 100) and Ptolemy (bk. 1 Almagest, ch. 7) rightly prove from this that all Heavy bodies are carried to one point, which within the Earth is equally distant from the convex surface of the terrestrial globe; and such a point is the center of the Earth. On the other hand, if not some [heavy bodies], nor [only] sometimes, but all heavy bodies and always are carried to one and the same terminus — and that naturally and from within — it follows that it is the terminus to which they are carried not per accidens but per se: therefore the center of the Earth really and in fact is that terminus, toward which all heavy bodies naturally tend per se.

[Margin: 1st proof of the Minor.]

The Minor is proved, first, by a proof exclusive [excluding] the center of the Earth: because even if the Earth were not where it is, but were annihilated or transferred elsewhere, the Water nevertheless — the Earth taken away — would descend into the place where the Earth had been; and if the Water were again taken away, Air would succeed, descending, into the place of the water, by a natural descent — as reason (leaning not indeed on these but on similar experiments), and Aristotle (4th On the Heaven, texts 22 & 39, already adduced above) teach. For we see that, the part of the earth on which the water lay being taken away, the water descends into the place where the part of earth was; and into the place where the water was, air descends. But the account of the whole element and of the part is the same, and the motion [is] of the same species, from the same principle, and to the same terminus — as the Philosopher taught more than once (especially 2nd On the Heaven, texts 96 & 102). Nor should you say that the air and water would then descend [merely] to fill the vacuum, and so not naturally but by force and by attraction; for both the water and the air itself have something of gravity (as Aristotle proved by the experiment of the [wine-]skin, 4th On the Heaven, text 30); therefore by the force of innate gravity, and not by attraction, they would run down to fill the vacuum, and at the same time to obtain the place owed to the heavier [body]. Therefore the center of heavy bodies would then not be the center of the Earth (as non-existent, or existing elsewhere): wherefore, if the center of Heavy bodies can be separated from the center of the Earth, the center of the Earth is not per se the terminus to which heavy bodies are carried per se (inasmuch as it is the Earth’s center), but per accidens. Which proof Aristotle does not express, but nevertheless hands down implicitly in the said texts.

[Margin: 2nd proof of the Minor.]

Secondly, the Minor is proved by an inclusive proof, which is Aristotle’s (2nd On the Heaven, text 99). For that is the terminus to which heavy bodies are carried per se which is the terminus from which, to the opposite terminus, light bodies are carried — since, along the same line (making similar angles everywhere), the former descend and the latter ascend, as is said there, and (4th On the Heaven, text 33), and is clear by experiment. But Light bodies are carried toward the extreme surface of the universal place which contains the middle of the world — that is, toward the extreme surface of the heaven — and indeed by a perpendicular ascent, and at angles similar (with respect to the celestial surface) to those which heavy bodies, in descending, make at the earth’s surface (if we stand by the judgment of the senses, as we ought, so long as nothing is evidently or from a higher authority established to the contrary). Therefore the terminus from which light bodies recede is the middle, or center, of the world; and so it is the same as the terminus to which heavy bodies are carried per se. Thus it has pleased me to propose Aristotle’s argument, so that its force might exert itself to the utmost. Yet two distinguished Copernicans, Galileo and Kepler, report it in other nearly equivalent words, answering it, however, otherwise.

[…continues on p. 443 (PDF 478) with the catchword “VI. Ga-” (VI. Ga-lilæus) — ¶VI, Galileo’s threefold response to this argument.]

(printed p. 443 — within Chapter XXV: the responses to Argument I. Galileo’s threefold reply (Aristotle presupposes the disputed identity of the Earth’s and the World’s centers, committing a paralogism; heavy bodies unite with their whole, not with an unattracting void center) is reported, then Kepler’s answer that heavy and light are only comparative, in which Riccioli finds five faults. Riccioli’s own response concedes the Major but denies the Minor: heavy bodies tend to the center of the elementary sphere, not to the World’s center as such.)

[Header: DE SYSTEMATE TERRÆ MOTÆ — 443]

[Margin: The same argument proposed and solved by Galileo.]

[VI.] For Galileo (Dialogue 1, On the System of the World, Italian page 26, Latin 20) introduces Simplicius thus disputing with Salviato: In the second place, you call into doubt whether the parts of the Earth too are moved, as Aristotle affirms, to the center of the World — as though indeed he had not conclusively demonstrated this by [the argument from] contrary motions, when he argues in this manner: The motion of heavy bodies is contrary to the motion of light bodies. But the motion of light bodies, as it appears, tends directly upward — that is, toward the circumference of the World; therefore the motion of heavy bodies tends straight toward the center of the World; and it happens per accidens that it tends toward the center of the Earth, since those centers coincide by chance.

[Margin: 1st Solution of Galileo.]

From which argument I gather, from Galileo (in the same place), a threefold response. The first is that by which he implicitly denies the Minor of the argument proposed by Simplicius; because, although fire tends straight upward to a circumference greater than the terrestrial circumference (of which kind is the concave of the Lunar heaven, toward which Aristotle more than once concedes that Fire tends), yet it does not follow from this that that very [circumference] is the circumference of the Universe, or of the supreme heaven, or concentric with the World;

[Margin: Aristotle accused of a paralogism by Galileo, and defended by Chiaramonti — but not sufficiently.]

nor can this be affirmed, unless it be presupposed that the center, from which we see light bodies ascend, is the same as the center of the World — and so that the center of the terrestrial globe is the same as the center of the World. But this very thing is what we doubt, and concerning which Aristotle himself proposed the doubt (text 99 of the second On the Heaven): accordingly Galileo affirms that Aristotle, by supposing that which is in question, manifestly commits a paralogism. But Chiaramonti (bk. 12, On the Universe, ch. 22) defends Aristotle, saying that in that text 99 he did not intend to prove that heavy bodies are carried downward — for that he supposed from common sense and from a most-received axiom, [namely] that heavy bodies are carried downward to the lowest place of the world, and that this is the center of the universe — but that he intended to prove that heavy bodies are carried not to the center of the Earth per se (and inasmuch as it is the Earth’s center), but inasmuch as it is the center of the World. But granted he did not wish to prove that heavy bodies tend downward, he nevertheless wished to prove that heavy bodies tend to the center of the universe, from the fact that they tend per se thither whence the light bodies recede by ascending straight upward; but he supposed this [terminus] to be the middle of the universe, because he supposed the circumference toward which [the light bodies] are carried to be the World’s circumference; and that he should suppose this rather than [the circumference] of some other sphere eccentric to the world, had its origin from nowhere else than from a preconceived opinion — that the World’s circumference was described from the center from which light bodies recede and toward which heavy bodies tend, that is, from the center of the Earth. Hence it is that, without other demonstration, he affirmed (2nd On the Heaven, text 98, and 4th On the Heaven, text 33) that the center of the Earth and the center of the Universe are the same. Wherefore, although Aristotle (2nd On the Heaven, text 101) concluded that the Earth is in the middle of the World, since nevertheless he did not prove it except by supposing that its center is the same as the center of the World, he seems to have supposed what was in controversy — and what he himself, a little before (text 73), had related to be denied by the Italian Pythagoreans.

[Margin: 2nd Solution of Galileo.]

Secondly, Galileo (in the same place, under the person of Sagredo): even if it were conceded that the circumference toward which fire tends straight is the circumference of the World, he denies nevertheless that it follows that heavy bodies descending along the same line tend to the center of the World — unless it be supposed that that line is produced all the way to the center of the World, and is wholly traversed by their descent. For from any point within a circle (even if it be very distant from the center) a straight line can be drawn toward the circumference, indeed produced up to the circumference itself, in which line an ascent and descent may take place without crossing, in the descent, the said [off-center] point, and accordingly without reaching the center.

[Margin: 3rd Solution.]

Thirdly, Galileo (on the following page, under the person of Salviati) denies that heavy bodies are carried per se to the center not of the Earth but of the Universe; for the center of the Universe is uncertain whether it exists, and where, on account of the infinity — or at least the vastness — of the world beyond what we see; and because nothing [the void], being destitute of all faculty, [cannot attract]; whereas the center of the Earth is certain, and to it heavy bodies are carried, that they may be united to their whole and may flee for refuge to their universal mother.

[Margin: The center of the World unfit to terminate per se the motion of Heavy bodies.]

Which objection — concerning the center of the World [being] unfit to move and attract by way of an end, or to terminate per se the motion of heavy bodies — Kepler too urges (bk. 1 of the Epitome of Copernican Astronomy, p. 95) and Gassendi (epistle 2, On impressed motion).

[Margin: The same argument proposed and solved by Kepler — but insufficiently.]

[VII.] Kepler, moreover (bk. 1 of the Epitome of Copernican Astronomy, p. 99), proposes Aristotle’s argument thus: He proved, [did] Aristotle, that the motion of heavy bodies tends to the World’s center, from the fact that the motion of light bodies is to the surface of the World — since the motions of heavy and light bodies tend to contrary regions. To which argument he subjoins a response, laboring under a greater fault than Aristotle’s argument seems to labor under. For he says that heavy and light are not called [so] absolutely, but only comparatively; otherwise, if fire and smoke were absolutely light, they would fly off from the Earth all the way to the outermost heaven — whereas in fact clouds of smoke, having surpassed the lowest region of the air, rest hanging [suspended]; which is an argument, he says, that they do not per se by their own nature seek the World’s extremes, or even flee from the earth’s center, but are pressed by heavier [bodies], and yield to them — as one pan of a balance (though heavy) seeks the higher [position] because it is drawn [down] by the other heavier [pan]. Which said, he concludes: Therefore it is false that light bodies of themselves seek the higher [regions]; false that they seek the World’s surface itself.

[Margin: Five faults in Kepler’s solution.]

But this response errs in many ways. First, it is false that there is not something which is absolutely heavy or light; for that which per se subsides beneath all in the elementary sphere is absolutely heavy, and that which rises above all is absolutely light: but there is in the elementary sphere some body which per se subsides beneath all, and a body which rises above all. Secondly, it is false that, if there were something absolutely light, it would reach all the way to the outermost heaven; for it would suffice for it to reach above all the other elementary bodies heavier than itself, or less light. Thirdly, he falsely assumes clouds of smoke as an example of simply light things, since they retain something of watery gravity, and accordingly do not even reach the supreme region of the air, and are heavier than pure air. Fourthly, he falsely gathers, from the suspension of clouds, that neither these nor all light bodies are moved upward per se and from within, but are thrust out by the heavier, denser parts of the air; for we have, from elsewhere, arguments physically showing positive levity, and the motion of light bodies upward per se and from within, as we have taught elsewhere; and at least that thrusting-out ought not to be assumed as certain (for excluding the earth from the World’s center), since it is more uncertain than this. Fifthly, finally, he falsely attributes to Aristotle that statement — namely, that light bodies seek the outermost surface of the World; for he only said that they tend toward the extreme surface of the World; nor does it follow, if someone say that he is going to sail toward Africa, that he wishes to arrive in Africa. Wherefore the first and second solutions of the Aristotelian argument adduced by Galileo (for concerning the third there will be a question below) are more solid than the Keplerian. Now we must respond to the same argument, but [as] proposed by us.

[Margin: Response. — Our [response] to Argument 1.]

[VIII.] I respond, then, to the 1st Argument proposed at number 5, the Major being conceded, by denying the Minor; and to its First proof it can be responded, on behalf of the Copernicans, that if the whole Earth were transferred elsewhere, all heavy bodies would be carried thither too — indeed, the whole elementary sphere would have to be transferred thither with the Earth, unless a new miracle were made in this. But the Earth being utterly taken away or annihilated, then the heaviest of the remaining elements would succeed into its place, and its center would now per se become the center of heavy bodies — not inasmuch as [it is the center] of Water, but inasmuch as [it is the] center of the body then heaviest in the World; or at least inasmuch as [it is the] center in which the heaviest body of all (namely the Earth) ought naturally to exist. But it does not follow from this that the Earth’s center — at least when it exists — is not per se the terminus toward which [the motion] of all heavy bodies [tends], and from which [the motion] of all light bodies [tends]. Just as the outermost surface of the eighth sphere (being the supreme of the celestial [spheres]) is, for Aristotle, per se the universal place of all visible things — granted that, if it were destroyed and the Sphere of Saturn remained, this [Saturn’s sphere] would now become the most universal place, and containing all.

[Margin: Response to the 2nd proof of the Minor.]

To the Second proof of the Minor I deny the Consequence; for granted it be conceded that light bodies, from wherever on earth, are carried along a line falling perpendicularly upon the outermost surface of the World, it does not follow from this that they are carried to that surface per se, but per accidens — inasmuch as that [surface] is exterior to, and concentric with, the sphere of the elements, to whose last surface light bodies tend per se. Wherefore, if light bodies per se tend to the last surface of the elementary sphere, per se they also recede from its center; and so heavy bodies per se are carried to the center of the elementary sphere — not inasmuch as it is the same with the center of the World, but inasmuch as [it is the center of] the elementary [sphere]…

[…continues on p. 444 (PDF 479) with the catchword “sphæ-” (elementaris sphæ-ræ) — “…of the elementary sphere,” completing Riccioli’s distinction between the center of the elementary sphere and the center of the World.]

(printed p. 444 — within Chapter XXV: Riccioli finishes his response to Argument I, then proposes and answers the Second Argument (from the perpendicular ascent of light bodies — conceded physically but denied under astronomical rigor, the Great Orb being point-like to the fixed stars), the Third (from the formal terminus of motion — a determined place need not be immovable), and the Fourth (why the whole Earth does not fall — Kepler and Gassendi deny the whole Earth is heavy, which Riccioli rebuts, since its parts have gravity even while adhering).)

[Header: BOOK IX. SECTION IV.]

…of the [elementary] sphere’s center. But the Order of the Elements demands that the center of the elementary sphere be the center of the Earth first — by a certain priority of foundation and of nature — rather than [the center] of the other bodies. Therefore the terminus per se, to which heavy bodies and from which light bodies are carried, is, by a stronger reason, the center of the Earth as Earth, than the center of the universe as it is the center of the universe. Next, neither the Pythagoreans nor the Copernicans would concede that light bodies ascend, from wherever on earth, at right angles made on the surface of the last heaven in Geometrical rigor, but only sensibly — both because they say that the whole Great Orb (through which they carry round the Earth’s center) is like a point in relation to the immense sphere of the Fixed [stars], and because the curved line, along which they say light bodies really ascend, is not perceived by us, [we being] carried along together with the Earth.

II. Argument for the Identity of the Earth’s center with the center of the World, from the Perpendicular Ascent of Light bodies toward the last Heaven

[Margin: 2nd Argument. Form.]

[IX.] Any light bodies whatever, let go from any point of the convex surface of the terrestrial globe, ascend along a line not only straight, but also falling perpendicularly — both upon the convexity of the earth and upon the concave of the celestial hemisphere seen by us (or of the visible World). Therefore they ascend from the middle of the World. But the same middle whence they ascend is the middle of the Earth. Therefore the middle (or center) of the Earth and of the World are the same.

[Margin: Proof of the Major.]

About the Minor, Pythagoreans and Copernicans agree with the Peripatetics, nor do the experiments permit [us] to doubt it. The Antecedent of the Major is proved both by the authority of Aristotle (2nd On the Heaven, text 99, and 4th On the Heaven, text 33, taken together) and by the experiment of the eyes; for we see, wherever on earth we are placed, the whole hemisphere of the supreme heaven (or of the visible World), and [we see] light bodies ascend straight to it in such a way that the line of ascent — produced by imagination — makes equal angles on both sides: mixtilinear, indeed, with the circumference passing through our zenith; but rectilinear, nay even right [angles], with the other straight line conceived to touch the convex surface of the last heaven at that point on which the straight line of the light bodies’ ascent falls. And the Consequence of the Major is proved, because it is impossible for a smaller sphere to be so inscribed within a greater that, from any point of the convexity of the smaller sphere (from which perpendiculars are drawn to the surface of the greater), the hemisphere of that same greater [sphere] can be seen — unless they are concentric; nay, unless the smaller be so small that the whole of it can be reckoned as the Physical center of the greater (which is easily clear from Geometry).

[Margin: Response to Argument 2.]

I respond: granted that the World is finite and spherical, and that what we see of it is reckoned by all as a hemisphere (for the common crowd — ignorant of the fallacies of sense and of Optics — reckons the upper parts of the World as a [vaulted] chamber, or a furnace’s vault, depressed in the middle and nearer to us than its extremes lying upon the horizon) — these things being granted, I say, conceding the whole Major physically and optically (or as to the appearance to the senses): both because the distance of the supreme heaven is so great that not only the globe of the earth, but even the Great Orb (in which either the Sun or the Earth is carried) is like a point, and so [the eye] cannot discern any inequality of the said angles; and because, if our own senses be supposed transferred with the Earth, they cannot discern this common motion of heavy bodies (really made along a curved line), but are forced always to see those appearances in the same straight line. But I deny the Major as to Astronomical rigor, according to which it is now asked whether the Earth is at the World’s center, or distant from it only by as much as the Sun is from it [the Earth]; for it can be so distant, the said phenomena being saved.

III. Argument, from the formal Terminus of the motion of Heavy and Light bodies

[Margin: 3rd Argument. Form.]

[X.] Gravity and Levity have been given to bodies by God and by Nature, so that, if they be outside their place, they may return to it — not that they may be joined to their wholes [which are] similar to themselves, but that they may tend to their proper place in the World inasmuch as it is a place, heavy bodies indeed downward, light bodies upward. Therefore they have their determined place in the World. Therefore the Earth and all Heavy bodies are carried to the center of the World, but Light bodies from the center of the World.

The Antecedent was proved most acutely by Aristotle (4th On the Heaven, texts 22, 23, & 24, related above). The first Consequence is proved, because the motion of heavy and light bodies as such is not spontaneous (as in animals), nor free (as in men), but is determined by nature; and so they are said to be moved by their generator — because he who generates them co-generates in them the principle determining them to one mode of operating and of moving themselves: therefore, if their local motion is determined, so too [is] the proper terminus, namely a place in the World. The second Consequence is proved, because every other place outside the center of the World is, with respect to heavy and light bodies, indeterminate by its nature and indifferent; for no reason appears why heavy bodies should tend to it rather than to another place in the World.

[Margin: Response to Argument 3.]

I respond: granting the antecedent (which, however, Copernicus, Gilbert, Kepler, and Galileo deny — maintaining that gravity and levity are nothing else than the inclination of the parts to tend toward the primary globes, or toward kindred and similar bodies), [I respond] by denying both the first Consequence — if by “determined place” be understood a fixed and immovable place — and the second; because if the Earth’s center is naturally carried along the circumference of the Great Orb, any points of the circumference are determined, at their own moments of the year, to that office; and thence, at such a time of the year, is taken the reason why heavy bodies should tend to such a point in the World rather [than another].

IV. Argument, from the Denial of the Descent of the whole Earth downward

[Margin: 4th Argument. Formula.]

[XI.] If the center of the Earth is not at the center of the World, no suitable reason can be brought why the whole Earth is not carried either downward, or toward that quarter of the world toward which the parts of earth located outside it are carried; but [a reason] can [be brought] if it is at the center of the World. Therefore the center of the Earth is at the center of the World.

The Antecedent is proved, because all the other reasons which others have tried to adduce have been sufficiently refuted by Aristotle (2nd On the Heaven, ch. 12, from text 77); and otherwise there is no reason why the Earth should rest in one part of the World rather than another — [if] placed outside the center of the World — and not be carried whither the parts are carried; for (from 2nd On the Heaven, texts 96 & 102) whither the parts are by their nature carried, thither the whole too is born to be carried. On the contrary, if it is at the center of the World, it will be equidistant from every quarter of the World, and so there will be no reason why it should be carried into one rather than another, and accordingly it will stand there unmoved.

[Margin: Response of Kepler and Gassendi.]

Kepler (in the Epitome of Copernican Astronomy, bk. 1, p. 102) and Pierre Gassendi (Epistle 2, On impressed motion, p. 113) respond by denying the antecedent, [saying] that the cause is that the whole Earth, as a whole — and compacted from parts now united to itself — is not heavy, because there is nothing outside the earth which attracts it magnetically (says Kepler); or because, as Gassendi says, gravity is an affection not of the whole Earth, but of the parts torn away from it. For the globe of the earth, considered whole in itself, does not need a motion by which it may betake itself to its place — from which it never departs, since it itself is its own place. For this motion, he himself says, is unitive of the parts, and congregative of them into one; and so, both from the part inhabited by us and from the part of the Antipodes, and from everywhere, they conspire to the same [center]; but it is not congregative of the Earth with any other body.

But this response does not satisfy; because if by the name “gravity” is understood the gravitating itself, the question is precisely about this — why it does not gravitate toward a place designable outside itself; but if “gravity in first act” [the disposition] is understood, the parts do not acquire it from the separation itself, or from that which separates them from their whole — for often such a separating-agent is unfit for that, as fire hurling up the rocks of Vesuvius, or a cannon hurling a ball; therefore they are presupposed to have had [gravity] even when they adhered to the Earth. Wherefore the whole Earth, consisting of similar parts, has gravity; and rightly Aristotle (2nd On the Heaven, text 77): Perhaps it would be [the mark] of a rather irrational mind not to wonder how…

[…continues on p. 445 (PDF 480) with the catchword “modo” (quonam modo parua terra particula) — completing Aristotle’s text 77, “…how a small particle of earth, if raised and let go, is borne down and will not rest, yet the whole Earth would rest.”]

(printed p. 445 — within Chapter XXV: Argument IV’s response concludes (with a critique of Chiaramonti’s computation of the Earth’s weight and a better second response), then Arguments V through VIII are proposed and answered: from the translation of the Earth to the Moon’s place, from the lowest place owed to the heaviest body, from Aristotle’s definitions of heavy and light — each resolved by referring the terminus to the elementary sphere’s center rather than the World’s — and from the destruction of positive levity, whose first response begins.)

[Header: DE SYSTEMATE TERRÆ MOTÆ — 445]

…how a small particle of earth, if raised up and let go, is borne [down] and will not rest (and the greater [part] always more swiftly); yet the whole Earth, if one should let it go when he had raised it, would not be borne [down], but now [its] so great gravity rests? And in the first [book of the] Meteorology, ch. 4, he said: In the middle, then, and around the middle, is the heaviest and the coldest.

[Margin: The weight of the whole Earth badly investigated by Chiaramonti.]

Granted, I do not approve the attempt of Chiaramonti (bk. 12, On the Universe, in the appendix to ch. 13), who, by weighing a cube of our [local] kneaded earth, thought — from its proportion to the cubes contained in the earth’s globe — that he could arrive near to the weight of the whole Earth; not only because within the Earth there are many waters and many caverns (which he himself admits), but because the cube of earth which he used — however kneaded and compressed — was much lighter than a cube of pure Earth, such as is in the bowels of the earth. Which is proved thus: that he there says that cube was one inch of the Cesena foot high (whose figure he there exhibits in a linear diagram), and is [equal to] two inches of the old Roman foot; and that this earthen cube weighed 7½ inches [i.e. ounces]. But a cube of this kind made of lead — which however, by his own concession in the same chapter 13, ought to be lighter than an equal cube of pure Earth — weighs two pounds and more. Therefore, by multiplying (as he himself does) the inch-cubes which are in the mass of the earth by 7½, we do not attain near to the truth of the weight of the whole Earth — granted he says the whole Earth weighs 2,711,787,896,857,350,340,085,118 pounds.

[Margin: 2nd Response to Argument 4.]

It can therefore be better responded, the Copernicans’ hypothesis being saved, by denying the Antecedent, and stating that the cause why the whole Earth — although most heavy — is not carried apparently along a straight line toward the center of the World, is that by its own nature it is determined to a circular motion about the center of the World, so that it ought always to be equidistant from it; while its parts do not gravitate except toward the center of the Earth itself.

V. Argument, from the Translation or Dissipation of the Earth into another place

[XII.] If the whole Earth were transferred to where the Moon now is, heavy bodies would not be carried to it, but to the center of the World; but if the whole Earth were divided into particles which were transferred elsewhere, they would not return elsewhere than to the center of the World. Therefore the center of the Earth and of the World are the same.

The Antecedent is gathered from Aristotle (bk. 4, On the Heaven, text 22). Therefore, etc.

[Margin: Lunar waters adhering to the Moon, per Kepler.]

Galileo will respond (Dialogue 2, On the System of the World, Latin p. 181) by denying the Antecedent: for he says that, the aggregate of heavy bodies being transferred to whatever place, the parts separated from the whole would flow together thither [to the new location]. But much more would Kepler deny the same antecedent, since (bk. 1, Epitome of Copernican Astronomy, p. 100) he affirms that there are waters in the Moon — and indeed heavy ones — and yet they do not fall down to the earth, much less to the center of the World, because they are kindred to the Lunar globe, and cohere with it by the Magnetic force of the Lunar globe; and so he denies that all heavy bodies flow together to the center of the Earth.

VI. Argument, from the Place owed to the Heaviest and Lowest of bodies

[Margin: 6th Argument. Form.]

[XIII.] To the heaviest and densest of bodies is owed the lowest place in the World. But the Earth is the heaviest, densest, and lowest of bodies, and the lowest place of the World is its center. Therefore the Earth’s center ought to be at the center of the World.

[Margin: Response to Argument 6.]

It is responded by conceding the Major concerning the lowest place in the order of the elementary system (or in that part of the World which consists of heavy and light bodies) — in which sense the Copernicans deny the second part of the Minor; but absolutely, and in the order of the universal system, they will deny the Major — in which sense they will concede the Minor.

VII. Argument, from the Definition of Heavy and Light bodies

[Margin: 7th Argument. Form.]

[XIV.] If the Earth were not at the center of the Universe, the commonly-received definition of Heavy and Light bodies would not be good; but the consequent is absurd; therefore also that from which it follows: and so the Earth is at the center of the Universe.

The Minor is clear. The Major is proved: for the definitions of these [heavy and light], handed down by Aristotle (bk. 4, On the Heaven) and commonly received, are three, but on account of the equivalence of the terms they conspire into one. For (text 6) it is said: Simply, then, we call Light that which is carried upward and to the extreme; but simply Heavy, that which [is carried] downward and to the middle. Then (text 26): First, indeed, let it be defined as it seems to all: the simply Heavy is that which subsides beneath all; but the Light, that which rises above all. Finally (text 31): But I call simply Light that which is always born to be carried upward when not prevented; and Heavy, that which [is always born to be carried] downward. Now, from the first definition, and from 4th On the Heaven, text 4, to be carried downward and to be carried to the middle of the World are the same; and nothing can subside beneath all unless it be at the center of the Universe. Therefore, if the Earth, which is simply heavy, were not at the center of the Universe, the definition of Heavy and Light simply would not stand.

[Margin: Response to Argument 7.]

It is responded by denying the Major; to whose proof, if by “middle” be understood the middle of the Elementary system (or of the aggregate of Heavy and Light bodies as such), it is conceded that Aristotle’s definitions can be commonly received — granted that not even thus were they received by the Platonists, who (on Aristotle’s own testimony, 4th On the Heaven, texts 8 & 9) defined the Heavy to be that which consists of more [parts] of the same [kind], the Light that which [consists] of fewer; or the heavy that which consists of more triangles, the light of fewer; nor by those who distinguished the Heavy from the full and the Light from the void (or from more voids) — namely Democritus and Leucippus, whom however Aristotle presses from text 12 to 20 of book 4 On the Heaven; nor, finally, by the Copernicans, who hold that Gravity is the inclination of tending toward one’s whole, and that Levity consists in a lesser gravity. But if by “middle” be understood the center of the Universe and of the whole mundane system, it is denied that those definitions must necessarily be received — except by those who, from elsewhere, presuppose that the center of the elementary system is the same as the center of the World; for by those who do not suppose this, but either deny it or call it into controversy, they are not necessarily to be admitted. And it suffices, for the essential coordination of Heavy and Light bodies, if the Heaviest subsides beneath all, and the Lightest rises above all, and the heavier subsides beneath the lighter, along a straight line drawn from the center of the elementary sphere.

VIII. Argument, from the Destruction of Positive Levity

[Margin: 8th Argument. Form.]

[XV.] If the center of the Earth and of the elementary system be not at the center of the World, positive levity is taken away, and is resolved into a privation of greater gravity. But this is absurd. Therefore, etc.

[Margin: Proof of the Major.]

The Minor is clear from the experiments and reasons adduced in ch. 16, nos. 3, 4, & 5. The Major is proved both by the consensus of the Copernicans — who, with Copernicus (bk. 1, ch. 8), deny that positive levity is given (as Kepler denies, bk. 1 Epitome of Copernican Astronomy, p. 99; Galileo, in the treatise On things that float on waters; and Gassendi, in the Epistle On impressed motion, pp. 118 & 119) — and by reason: because, granted the globe of Earth, Water, and Air can be the place to which heavy bodies tend according to their gravity (even if this globe be transferred, since they at length have a center to which they direct their motion and descent — namely the point which is on the circumference of the Annual orbit), nevertheless no place can be assigned to which, as proper, light bodies might congregate by ascent — since they are forced at once to desert it, nor is there in the mundane space a place toward which they ought by their nature to strive by an intrinsic principle of motion.

[Margin: 1st Response to Argument 8.]

I respond, first, by denying the Major: for the place of Light bodies — say, of elementary fire, if it be given — is a portion of the elementary sphere, placed within the concave of the Moon and the supreme region of the air, to which the particles of fire carried thither adhere no less than the particles of earth adhere to the earth. And just as the particles of earth, although on account of the translation [motion] of the elementary system they lose, in the World’s space, that place which the whole earth too loses — that is, the remote place, and (as others say) the mathematical [place] — yet they do not lose the prox[imate]…

[…continues on p. 446 (PDF 481) with the catchword “ximum” (pro-ximum) — “…the proximate [place],” completing the response that light bodies, like heavy ones, keep their proximate place within the moving elementary system.]

(printed p. 446 — Chapter XXV closes with Arguments IX–XI against the annual motion, after finishing the response to Argument VIII on fire-particles and dismissing a Gassendist denial of positive levity. Argument IX urges that an off-center Earth confounds heavy with light; X, that gravity’s end is rest in place; XI, that the Copernicans needlessly multiply centers. Riccioli answers each, turning the last back against the Copernican hypothesis itself.)

[Header: BOOK IX. SECTION IV.]

…[the prox]imate and physical place; so neither [do] the particles of fire [lose theirs] — although the elementary system, with the Lunar heaven, is carried round elsewhere.

[Margin: 2nd Response, but frivolous.]

Not a few will respond, secondly, by denying the Minor, with Epicurus, Democritus, and Leucippus — whom Copernicus followed implicitly (bk. 1, ch. 8), but Galileo explicitly (in the treatise On things carried in waters), Kepler (bk. 1, Epitome of Copernican Astronomy, p. 99), and Gassendi (epistle 2, On impressed motion, p. 118); for they said that levity consists in the mere privation of greater gravity, and that Fire is therefore called the lightest because it is the least heavy of all — that is (adds Gassendi) because it is the least of all bodies drawn by the Earth; and that the things we call light do not ascend upward by the force of an intrinsic principle, but are thrust up by the heavier [bodies], which strive to occupy the lower place owed to themselves.

[Margin: Gassendi’s objections against positive Levity.]

To confirm which he adduces certain [arguments], which persuade [us] that there is a double levity — one which he attacks by such weak arguments, the other being that very levity of the arguments. First, he says that fire does not burn in a fireplace if the room is so closed that no air can enter through any chink; but if the chimney is open, why does the air which is in the room not thrust the fire upward? (For if, in this case, the fire is carried upward, the experiment would be void.) If you say [it is] because so great a rarefaction of the air cannot happen so suddenly as to fill as much place as the flame occupied, then the cause why the fire does not ascend is not a defect of thrusting-out, but the difficulty of supplying the vacuum. Secondly, he says that the feet of one sitting by the fire are warmed in front, but the heels are cooled, the colder air running up to the heels toward the fire; but, granted the experiment be true, whence do you prove that it runs up in order to thrust out the fire, and not rather to succeed into the place of the flame flying up? Thirdly, he says that fire burns more vehemently if the wood lies upon an iron grate rather than upon the ash itself; but this happens not because the air beneath thrusts the fire up — for thrusting-out, in itself, cannot be the cause of a greater fire (since it supposes the whole fire, which is to be thrust out, as already existing) — but it happens because the matter nearest the ignition, and the flame itself, requires rarefaction round about, which is impeded, toward that part, by the ash. Fourthly, finally, he says that the chemists’ furnace, which they call “blast” [windy] — without any other bellows, by the air alone driving from below — ventilates and inflames the coals lying upon it. But who would doubt that the wind can impel the subtler parts and spirits of the fire, and crowd them into the pores of the coals, so that, united, they act more strongly and inflame the coals? Yet the same will happen even if they drive not from below but from above, as when we kindle coals placed under a fan. Let these, then, hold good [be dismissed] — and any [arguments] lighter than these, vainly devised against the levity of bodies.

IX. Argument, from the Confusion of Heavy bodies with Light, and vice versa

[Margin: 9th Argument. Form.]

[XVI.] If the Earth is outside the center of the World, nothing will be absolutely heavy or light, but the same [thing] which is called heavy will, at the same time, have to be called light, and what [is] light, heavy. The consequent is unfitting; therefore also the Antecedent, from which it follows.

The Major is proved, because, while that which is called heavy descends toward the earth, it will nevertheless at the same time recede from the middle (or center) of the universe; and what is called light, in ascending from the Earth, will approach the middle of the world; but what is carried from the middle is light, and what is carried to the middle is heavy; therefore the same [thing] will be at once heavy and light.

[Margin: Response.]

I respond by denying the Major and its proof, because, on the opinion placing the Earth outside the World’s middle, those definitions do not hold which distinguish heavy bodies from light by approach to the middle of the World.

X. Argument, from the End of the motion of Heavy and Light bodies

[Margin: 10th Argument. Form.]

[XVII.] Gravity and Levity are implanted in inanimate bodies, that they may rest in their place, and may not easily be moved from it; or, if they have been removed thence, may so return to it that they may rest there. Therefore the center of the Earth and of the whole elementary sphere is not outside the World’s center.

The Antecedent is proved, first, from the Philosopher (2nd On the Heaven, text 92), where it is said: For whither any particle of it (that is, of the Earth) is carried, thither the whole too must necessarily be carried; and whither anything is carried according to nature, there too it must necessarily remain according to nature. — Then, by reason: because by this is distinguished the end of the motions which are in animate things or in celestial bodies, from the end of the motion which is in the elements and inanimate mixtures: namely, that motion was given to animate [things] so that by a spontaneous motion they might acquire for themselves something beyond what they have from birth; and to the celestial [bodies], so that they might be moved not by acquiring [anything] for themselves, but for the sake of others; whereas to the Elements and inanimate [things], motion was given for neither [purpose], but precisely that they might retain and recover the place owed to them in the Universe. The Consequence is proved, because if the Earth is placed outside the center of the world for some cause — chiefly that through its motion many phenomena of the Sun and of the five lesser Planets may be more easily explained — then, if it is moved, neither it nor the rest of the elements retain their place in the World, but perpetually change it.

[Margin: Response to Argument 10.]

It is responded by conceding the Antecedent concerning the motion of Heavy and Light bodies as such; and in this sense the Consequence is denied. For, the Earth being carried round through the annual orbit, they do not change their place by gravitation and levitation (or inasmuch as they are Heavy or Light); for once they have reached their Physical place, they remain in it — granted they change their Mathematical place by the circular motion, which befits the Earth not as heavy, but as it is supposed to be a kind of Planet.

XI. Argument, from the unnecessary Multiplication of Centers, and of their Situation

[Margin: 11th Argument. Form.]

[XVIII.] The centers of systems in the World are not to be multiplied without necessity, and much less the situations of centers — finite [ones] [multiplied] to infinity. But if the Earth’s center is not the same as the center of the World, there are multiplied without necessity not only the centers of systems, but also — finite to infinity — the situations of centers. Therefore, etc.

The Major is certain from the axiom so often repeated above, and admitted by the Copernicans themselves. The Minor is proved, because hence it follows that the center of the system of the whole World is really diverse from the center of the system of the Elements (which is the same as the center of the Earth); and because the Earth’s center is supposed to be moved perpetually, it perpetually acquires other and other situations, to infinity. But these [things] happen without necessity, since, the identity of the center of the elements and of the World being posited, all the phenomena can be saved.

[Margin: 1st Response to Argument 11.]

It is responded, first, by denying the Minor; for the necessity, on the Copernicans’ opinion, is not indeed a posteriori, nor from those things which appear to sense, but is a priori, on account of that very axiom which was used in the Major — namely, that the centers of the Planetary system should not be multiplied; that is, that the Sun’s center, or the center of the annual orb, should not be placed diverse from the center of the World.

[Margin: 2nd Response.]

And therefore it is responded, secondly, by turning the argument back, and subjoining to the Major of argument 11 this Minor: But if the Sun’s center, or the center of the Great Orb, be not the same as the center of the World, there are multiplied without necessity the centers of the systems of the World and of the Planets; but if this necessity be proved from elsewhere, then this argument will be better formed against the Copernican hypothesis than against the opposite [one].

✠

[…Chapter XXV ends here (cross-ornament). Continues on p. 447 (PDF 482) with the catchword “CA-” (CAPVT) — CHAPTER XXVI: five further arguments against the annual motion, from the downward situation and the perversion of the mundane system.]

(printed p. 447 — Chapter XXVI opens: five arguments against the annual motion drawn from the downward situation of the Earth and the perversion of the mundane system. Arguments I–IV — from the universal judgment of up and down, the lowest body deserving the lowest place, the license of placing the Earth anywhere, and the situation of Hell — are stated with their responses. Argument V, from the Copernicans’ perversion of the elementary and planetary system, is stated and its response begun, continuing on p. 448.)

[Header: DE SYSTEMATE TERRÆ MOTÆ — 447]