§1.3#13 ἀναλαβόντες οὖν τὰς ἐξ ἀρχῆς θέσεις καὶ τοὺς εἰρημένους πρέτερον διορισμούς, λέγωμεν περί τε τῆς τοῦ γάλακτος φαντασίας καὶ περὶ κομητῶν καὶ τῶν ἄλλων ὅσα τυγχάνει τούτοις ὄντα συγγενῆ.
3 Therefore, let us take up again our original assumptions and the definitions previously stated, and speak of the appearance of the Milky Way, of comets, and of the other things that happen to be akin to these.
φαμὲν δὴ πῦρ καὶ ἀέρα καὶ ὕδωρ καὶ γῆν γίγνεσθαι ἐξ ἀλλήλων, καὶ ἕκαστον ἐν ἑκάστῳ ὑπάρχειν τούτων δυνάμει, ὥσπερ καὶ τῶν ἄλλων οἶς ἕν τι καὶ ταὐτὸν ὑπόκειται, εἰς ὃ δὴ ἀναλύονται ἔσχατον.
For we say indeed that fire, air, water, and earth come to be from one another, and each exists in each of these potentially, just as is the case for the other things which have one and the same underlying subject, into which they are finally resolved.
πρῶτον μὲν οὖν ἀπορήσειεν· ἄν τις περὶ τὸν καλούμενον ἀέρα, τίνα τε χρὴ λαβεῖν αὐτοῦ τὴν φύσιν ἐν τῷ περιέχοντι κόσμῳ τὴν γῆν, καὶ πῶς ἔχει τῇ τάξει πρὸς τἆλλα τὰ λεγόμενα στοιχεῖα τῶν σωμάτων.
First, then, one might raise a difficulty concerning the so-called air: what we ought to take its nature to be in the world surrounding the earth, and how it stands in order in relation to the other so-called elements of bodies.
ὁ μὲν γὰρ δὴ τῆς γῆς ὄγκος πηλίκος ἄν τις εἴη πρὸς τὰ περιέχοντα μεγέθη, οὐκ ἄδηλον· ἤδη γὰρ ὦπται διὰ τῶν ἀστρολογικῶν θεωρημάτων ἡμῖν ὅτι πολὺ καὶ τῶν ἄστρων ἐνίων ἐλάττων ἐστίν.
For the volume of the earth, of what size it might be in relation to the surrounding magnitudes, is not unclear; for it has already been seen by us through astronomical theorems that it is much smaller even than some of the stars.
ὕδατος δὲ φύσιν συνεστηκυῖαν καὶ ἀφωρισμένην οὔθ᾿ ὁρῶμεν οὔτʼ ἐνδέχεται κεχωρισ μένην εἶναι τοῦ περὶ τὴν γὴν ἰδρυμένου σώματος, οἷον τῶν τε φανερῶν, θαλάττης καὶ ποταμῶν, κἂν εἴ τι κατὰ βάθους ἄδηλον ἡμῖν ἐστιν.
But we neither see a constituted and defined nature of water, nor is it possible for it to exist separated from the body established about the earth, such as the visible bodies of the sea and rivers, and whatever is hidden from us in the depths.
τὸ δὲ δὴ μεταξὺ τῆς γῆς τε καὶ τῶν ἐσχάτων ἄστρων πότερον ἕν τι νομιστέον εἶναι σῶμα τὴν φύσιν ἢ πλείω, κἂν εἰ πλείω, πόσα, καὶ μέχρι ποῦ διώρισται τοῖς τόποις;
But as for the space between the earth and the outermost stars, is it to be considered as one body in nature or more, and if more, how many, and up to what point are they distinguished by their places?
ἡμῖν μὲν οὖν εἴρηται πρότερον περὶ τοῦ πρώτου στοιχείου, ποῖόν τι τὴν δύναμίν ἐστιν, καὶ διότι πᾶς ὁ περὶ τὰς ἄρω φορὰς κόσμος ἐκείνου τοῦ σώματος πλήρης ἐστί.
Now, we have spoken previously about the first element, what sort of thing it is in its power, and that the whole world around the upper motions is full of that body.
καὶ ταύτην τὴν δόξαν οὐ μόνον ἡμεῖς τυγχάνομεν ἔχοντες, φαίνεται δὲ ἀρχαία τις ὑπόληψις αὕτη καὶ τῶν πρότερον ἀνθρώπων· ὁ γὰρ λεγόμενος αἰθὴρ παλαιὰν εἴληφε τὴν προσηγορίαν, ἥν Ἀναξαγόρας μὲν τῷ πυρὶ ταὐτὸν ἡγήσασθαί μοι δοκεῖ σημαίνειν·
And this opinion happens to be held not only by us, but it appears to be an ancient assumption of those before us; for the so-called ether has received an ancient appellation, which Anaxagoras seems to me to have thought signified the same as fire.
τά τε γὰρ ἄνω πλήρη πυρὸς εἶναι, κἀκεῖνος τὴν ἐκεῖ δύναμιν αἰθέρα καλεῖν ἐνόμισεν, τοῦτο μὲν ὀρθῶς νομίσας· τὸ γὰρ ἀεὶ σῶμα θέον ἅμα καὶ θεῖόν τι τὴν φύσιν ἐοίκασιν ὑπολαβεῖν, καὶ διώρισαν ὀνομάζειν αἰθέρα τὸ τοιοῦτον ὡς ὂν οὐδενὶ τῶν παρʼ ἡμῖν τὸ αὐτὸ·
For he believed that the upper regions are full of fire, and he thought fit to call the power there "ether," thinking correctly in this respect; for they seem to have assumed that the body which is always running is at the same time divine in nature, and they determined to name such a thing "ether" as being the same as none of the things around us.
οὐ γὰρ δὴ φήσομεν ἅπαξ οὐδὲ δὶς οὐδʼ ὀλιγάκις τὰς αὐτὰς δόξας ἀνακυκλεῖν γιγνομένας ἐν τοῖς ἀνθρώποις, ἀλλʼ ἀπειράκις.
For we shall say that the same opinions recur among humans not once or twice or a few times, but infinitely.
ὅσοι δὲ πῦρ καθαρὸν εἶναί φασι τὸ περιέχον καὶ μὴ μόνον τὰ φερόμενα σώματα, τὸ δὲ μεταξὺ γῆς καὶ τῶν ἄστρων ἀέρα, θεωρήσαντες ἂν τὰ νῦν δεικνύμενα διὰ τῶν μαθημάτων ἱκανῶς ἴσως ἂν ἐπαύσαντο ταύτης τῆς παιδικῆς δόξης· λίαν γὰρ ἀπλοῦν τὸ νομίζειν μικρὸν τοῖς μεγέθεσιν εἶναι τῶν φερομένων ἕκαστον, ὅτι φαίνεται θεωροῦσιν ἐντεῦθεν ἡμῖν οὕτως.
But those who say that the surrounding region is pure fire and not only the moving bodies, and that the space between the earth and the stars is air, would perhaps have ceased from this childish opinion if they had sufficiently examined the things now demonstrated through mathematics; for it is too simple to think that each of the moving bodies is small in magnitude, because it appears so to us who observe from here.
εἴρηται μὲν οὖν καὶ πρότερον ἐν τοῖς περὶ τὸν ἄνω τόπον θεωρήμασι· λέγωμεν δὲ τὸν αὐτὸν λόγον καὶ νῦν, εἰ γὰρ τὰ τε διαστήματα πλήρη πυρὸς καὶ τὰ σώματα συνέστηκεν ἐκ πυρός, πάλαι φροῦδον ἂν ἦν ἕκαστον τῶν ἄλλων στοιχείων.
Although this has been spoken of previously in the theorems concerning the upper region, let us state the same argument now as well: for if the intervals were full of fire and the bodies were composed of fire, each of the other elements would have been vanished long ago.
ἀλλὰ μὴν οὐδʼ ἀέρος γε μόνου πλήρη· πολὺ γὰρ ἂν ὑπερβάλλοι τὴν ἰσότητα τῆς κοινῆς ἀναλογίας πρὸς τὰ σύστοιχα σώματα, κἃν εἰ δύο στοιχείων πλήρης ὁ μεταξὺ γῆς τε καὶ οὐρανοῦ τόπος ἐστίν· οὐδὲν γὰρ ὡς εἰπεῖν μόριον ὁ τῆς γῆς ἐστιν ὄγκος, ἐν συνείληπται πᾶν καὶ τὸ τοῦ ὕδατος πλῆθος, πρὸς τὸ περιέχον μέγεθος.
Nevertheless, they are certainly not full of air alone either; for it would far exceed the equality of the common proportion in relation to its coordinate bodies, even if the region between the earth and heaven is full of two elements; for the volume of the earth, in which is comprised also the whole quantity of water, is, so to speak, no fraction at all in comparison with the surrounding magnitude.