Lecture 20 — Opinions of the philosophers as to the site of the earth. Pythagorean theory, of fire in the center relected

337 It remains to speak of the earth, of its position, of the question whether it is at rest or in motion, and of its shape.

338 As to its position there is some difference of opinion. Most people—all, in fact, who regard the whole heaven as finite—say it lies at the center. But the Italian philosophers known as Pythagoreans take the contrary view. At the center, they say, is fire, and the earth is one of the stars, creating night and day by its circular motion about the center. They further construct another earth in opposition to ours to which they give the name counterearth.

339 In all this they are not seeking for theories and causes to account for observed facts, but rather forcing their observations and trying to accommodate them to certain theories and opinions of their own.

340 But there are many others who would agree that it is wrong to give the earth the central position, looking for confirmation rather to theory than to the facts of observation.

341 Their view is that the most precious place befits the most precious thing: but fire, they say, is more precious than earth, and the limit than the intermediate, and the circumference and the center are limits. Reasoning on this basis they take the view that it is not earth that lies at the center of the sphere, but rather fire.

342 The Pythagoreans have a further reason. They hold that the most important part of the world, which is the center, should be most strictly guarded, and name it, or rather the fire which occupies that place, the 'Guardhouse of Zeus',

343 as if the word 'center' were quite unequivocal, and the center of the mathematical figure were always the same with that of the thing or the natural center. But it is better to conceive of the case of the whole heaven as analogous to that of animals, in which the center of the animal and that of the body are different. For this reason they have no need to be so disturbed about the world, or to call in a guard for its center: rather let them look for the center in the other sense and tell us what it is like and where nature has set it. That center will be something primary and precious; but to the mere position we should give the last place rather than the first. For the middle is what is defined, and what defines it is the limit, and that which contains or limits is more precious than that which is limited, seeing that the latter is the matter and the former the essence of the system.

344 As to the position of the earth, then, this is the view which some advance,

479. After determining about the heavenly body which is moved circularly, the Philosopher here determines the question of the earth, around which the heaven is moved. But he does not intend to determine here concerning the earth as one of the four elements but as it is the center of heavenly motion, as astronomers deal with it.

First, therefore, he states his intention;

secondly, he pursues it, at as to its position (293a17; [480]).

He says, therefore, first (293a15) that, since the heaven has been discussed, there remains the earth to be discussed. Concerning this, he says there are for him three things to be settled:

first, its situation, namely, where is it positioned;

secondly, its rest, namely, whether it is one of the things that rest or that are moved;

thirdly, its shape, namely, whether it has a spherical shape or some other.

480. Then, at as to its position (293a17), he executes his proposal:

first he pursues the above-mentioned three things according to the opinion of others;

secondly, according to truth, at let us first decide (L. 26; 296a24).

Concerning the first he does two things:

first he presents the false opinions of certain ones concerning earth;

secondly, he presents the false reasons alleged about the true theory concerning the earth's state of rest, at the difficulty must have occurred (L. 22; 294a11).

As to the first he does three things:

first he presents others' opinions about the position of the earth;

secondly, about its rest and motion, at and the views advanced concerning its rest (L. 21; 293b16);

thirdly, about its shape, at there are similar disputes about the shape (L. 21; 293b32).

About the first he does three things:

first he presents others' opinions about the position of earth (293a17; [481]);

secondly, he gives their reasons, at in all this they are not seeking (293a25; [482]);

thirdly, he solves them, at as if the word 'center' (293b4; [485]).

481. He says therefore first (293a17) that not all philosophers have the same opinion about the position of the earth. For whichever ones held that the entire universe is infinite were unable to assign a definite position to the earth, since in the infinite no middle and no boundary can be determined. But a number of those who posited the whole world as finite said that earth is positioned in the middle of the world, as did Anaximander, Anaxagoras, Democritus, Empedocles and Plato. But certain philosophers called "Pythagoreans" who sojourned in the region of Italy said on the contrary that fire is positioned in the middle of the world and that the earth, after the manner of one of the stars, moved circularly around the center of the world, and by its motion makes day and night, according to its different relation to the sun. They also posited another earth—likewise in circular motion about the middle of the world—which they called antichtona on account of its contraposition to our earth. But this other earth is not visible to us because in its motion it follows the earth in which we live, in such a way that the entire body of our earth is always interposed between our sights and this other earth. And although the Pythagoreans said these things according to the face value of their words, they nevertheless understood in their metaphor that fire was in the center since the natural heat produced from the sun and other stars reaches the middle of the world, in a certain way keeping all things in balance and preserving them. But earth they said to be a star because it causes day and night, depending on its relation to the sun. The other earth they called a moon, either because it is interposed to the sun's light as our earth is, as is plain from eclipses, or because it is the boundary facing us of the heavenly bodies, just as the earth is the boundary of the elements.

482. Then, at in all this they are not seeking (293a25), he presents their reasons. Concerning this he does two things:

first he describes the quality of their reason;

secondly, he presents the reasons themselves, at their view is that the most precious (293a30; [483]).

About the first he does two things:

first he describes the kind of reasons the Pythagoreans used (293a25) and says that they did not search for reasons and causes in such a way as to apply them to what is sensibly apparent; rather, what was apparent to sense they tried to reduce to, and by a certain violence align with, certain preconceived intelligible reasons and opinions. Now such a method is suitable in things that are man-made, and whose principle is the human intellect; but in things that are the product of divine art, it is necessary, on the contrary, to consider the notions of the works from the works themselves that are seen. Thus an artisan conforms a house he makes to preconceived plans, but whoever else might see the constructed house would consider the ideas of the work from the sight of the work.

Secondly, at (293a27) he shows that it is possible for many others to be moved by these same reasons of the Pythagoreans. And he says that it might seem to many others besides the Pythagoreans that one should not assign the middle region to earth, if it is their wont to consider things, not as they appear, but according to intelligible reasons. He says this, not as though any of Aristotle's predecessors besides the Pythagoreans posited this, but because it was possible that others would be swayed by these reasons. Hence it is said that after Aristotle's time Archedemus was of this opinion.

483. Then, at their view is that the most precious (293a30), he gives two reasons.

The first of these is that they thought that the most honorable region, i.e., place, should belong to the most honorable body, on the ground that places are proportionate to bodies according to their nature. But it is plain that fire is more honorable than earth, not only because of its brightness, but also on account of its active power and on account of its subtility. It is plain, too, that boundaries are nobler than the intermediates between them, as the terminus is nobler than the thing terminated and a container than the contained. But that which is extreme, i.e., highest, in the world, and that which is the middle of the world, they thought of as being boundaries. For this reason, they set them down as the noblest places. And therefore, thinking in this wise, they did not place earth in the middle of the sphere of the world, but rather fire, which holds the place of nobility after the heavenly bodies, which are at the boundaries.

484. He gives their second reason, at the Pythagoreans (293b1) and says that the Pythagoreans put fire in the middle of the world because, since it is the most principal of the elements it should be most of all preserved—as we more carefully guard precious things. Now the middle place seems to have such a disposition for preserving, as though walled up and strengthened by all the things that surround the middle. That is why the Pythagoreans, speaking metaphorically, called this region which has fire, the guard-house or fortress of Jupiter. This is the case if we understand that the fire is guarded. But if we understand that fire is the guardian, then, conversely, we must understand that the fire which has this region, i.e., which holds the middle place, is Jupiter's guardhouse in the sense that it has the power of guarding.

485. Then, at if the word 'center' (293b4), he refutes the aforesaid reason and says that in the aforesaid reason the Pythagoreans used the word middle as though one called "middle" absolutely, i.e., univocally, both the middle of a magnitude, and the middle of a thing according to nature, i.e., that through which the nature of a thing is preserved—as we see in animals that the middle by which the nature of an animal is preserved, namely, the heart, is not the same as the middle of the body's size, for that would be the umbilicus. A similar viewpoint must be taken with respect to the whole heaven, i.e., to the whole universe. Hence they should not be concerned with the whole universe as though it needs a guardhouse in such a way that such a prison or guardhouse would have to be assigned to the center, which is the middle of magnitude. It is necessary, rather, to seek that which is the middle of nature in the universe, as in the case of an animal, and ask what is its condition according to nature, and which place naturally befits it.

He explains these two things, showing first how the middle of the universe is as corresponding to the heart of an animal. And he says that it is a principle of other bodies, and most honorable among other bodies: and this is the sphere of the fixed stars. But it is not the middle place but rather the place of the outermost container that belongs to it, for that which is the magnitudinal middle among the places of the universe is more like an ultimate than like a principle. The reason is that the middle is contained and determined by all the others, while that which is the end, i.e., the extremity, among bodies according to the order of place, has the nature of a determinant and container. But it is manifest that the container is more honorable than the contained, and the end more honorable than the thing ended—since the contained and the terminated pertain to the notion of matter, but to be a container and that which terminates to the notion of form, which is the substance of the whole consistency of things. Consequently, containing bodies are more formal and contained bodies are more material. And therefore, in the whole universe, just as the earth which is contained by all, being in the middle, is the most material and ignoble among bodies, so the outermost sphere is most formal and most noble, while among the elements fire is above all containing and formal.

Finally, he sums up (293b15) and concludes that in regard to the place of earth, some have an opinion such as has been described.