§3.2#2ἐκ διεστώτων δὲ καὶ κινουμένων οὐκ εὔλογον ποιεῖν τὴν γένεσιν.
But it is not reasonable to make generation out of things that are dispersed and moving.
διὸ καὶ Ἐμπεδοκλῆς παραλείπει τὴν ἐπὶ τῆς φιλότητος· οὐ γὰρ ἂν ἡδύνατο συστήσαι τὸν οὐρανὸν ἐκ κεχωρισμένων μὲν κατασκευάζων, σύγκρισιν δὲ ποιῶν διὰ τὴν φιλότητα· ἐκ διακεκριμένων γὰρ συνέστηκεν ὁ κόσμος τῶν στοιχείων.
Therefore Empedocles also omits the generation under Love; for he would not have been able to construct the heaven if he built it from separated things and made the combination by means of Love; for the world is constructed from elements that are separated.
ὥστʼ ἀναγκαῖον γίνεσθαι ἐξ ἑνὸς καὶ συγκεκριμένου.
Consequently, it is necessary for it to come to be from a single and combined thing.
ὅτι μὲν τοίνυν ἐστὶ φυσική τις κίνησις ἑκάστου τῶν σωμάτων, ἣν οὐ βίᾳ κινοῦνται οὐδὲ παρὰ φύσιν, φανερὸν ἐκ τούτων· ὅτι δʼ ἔνια ἔχειν ἀναγκαῖον ῥοπὴν βάρους καὶ κουφότητος, ἐκ τῶνδε δῆλον.
That there is, therefore, some natural motion for each of the bodies, in which they are moved neither by force nor contrary to nature, is clear from these considerations; but that it is necessary for some of them to have an inclination of weight and lightness is clear from the following.
κινεῖσθαι μὲν γάρ φαμεν ἀναγκαῖον εἶναι· εἰ δὲ μὴ ἕξει φύσει ῥοπὴν τὸ κινούμενον, ἀδύνατον κινεῖσθαι ἢ πρὸς τὸ μέσον ἢ ἀπὸ τοῦ μέσου.
For we say that it is necessary to be moved; and if the moving thing does not naturally possess an inclination, it is impossible for it to be moved either towards the center or away from the center.
ἔστω γὰρ τὸ μὲν ἐφʼ οὗ Αἀβαρές, τὸ δʼ ἐφʼ οὖ B βάρος ἔχον, ἐνηνέχθω δὲ τὸ ἀβαρὲς τὴν ΓΔ, τὸ δὲ B ἐν τῷ ἴσῳ χρόνῳ τὴν ΓΕ· μείζω γὰρ οἰσθήσεται τὸ βάρος ἔχον.
For let A be that which is weightless, and B that which has weight, and let the weightless thing be carried over the distance ΓΔ, and B in the equal time over the distance ΓΕ; for that which has weight will be carried over a greater distance.
ἐὰν δὴ διαιρεθῇ τὸ σῶμα τὸ ἔχον βάρος ὡς ἡ ΓΕ πρὸς τὴν ΓΔ (δυνατὸν γὰρ οὕτως ἔχειν πρός τι τῶν ἐν αὐτῷ μορίων), εἰ τὸ ὅλον φέρεται τὴν ὅλην τὴν ΓΕ, τὸ μόριον ἀνάγκη ἐν τῷ αὐτῷ χρόνῳ τὴν ΓΔ φέρεσθαι, ὥστε ἴσον οἰσθήσεται τὸ ἀβαρὲς καὶ τὸ βάρος ἔχον· ὅπερ ἀδύνατον.
If, then, the body having weight is divided in the ratio of ΓΕ to ΓΔ (for it is possible for it to have this ratio to some of its parts), if the whole is carried over the whole distance ΓΕ, the part must necessarily be carried over ΓΔ in the same time, so that the weightless thing and the thing having weight will be carried over an equal distance; which is impossible.
ὁ δʼ αὐτὸς λόγος καὶ ἐπὶ κουφότητος.
And the same argument holds also in the case of lightness.
ἔτι δʼ εἰ ἔσται τι σῶμα κινούμενον μήτε κουφότητα μήτε βάρος ἔχον, ἀνάγκη τοῦτο βίᾳ κινεῖσθαι, βίᾳ δὲ κινούμενον ἄπειρον ποιεῖν τὴν κίνησιν.
Furthermore, if there is to be some moving body having neither lightness nor weight, this must necessarily be moved by force, and being moved by force, it must make its motion infinite.
ἐπεὶ γὰρ δύναμίς τις ἡ κινοῦσα, τὸ δʼ ἔλαττον καὶ τὸ κουφότερον ὑπὸ τῆς αὐτῆς δυνάμεως πλεῖον κινηθήσεται, κεκινήσθω τὸ μὲν ἐφʼ ᾧ τὸ A, τὸ ἀβαρές, τὴν ΓΕ τὸ δʼ ἐφʼ ᾧ τὸ B, τὸ βάρος ἔχον, ἐν τῷ ἴσῳ χρόνῳ τὴν ΓΔ. διαιρεθέντος δὴ τοῦ βάρος ἔχοντος σώματος ὡς ἡ ΓΕ πρὸς τὴν ΓΔ, συμβήσεται τὸ ἀφαιρούμενον ἀπὸ τοῦ βάρος ἔχοντος σώματος τὴν ΓΕ φέρεσθαι ἐν τῷ ἴσῳ χρόνῳ, ἐπείπερ τὸ ὅλον ἐφέρετο τὴν ΓΔ. τὸ γὰρ τάχος ἔξει τὺ τοῦ ἐλάττονος πρὸς τὸ τοῦ μείζονος ὡς τὸ μεῖζον σῶμα πρὸς τὸ ἔλαττον.
For since the moving thing is some power, and the smaller and lighter thing will be moved further by the same power, let A, the weightless thing, be moved over the distance ΓΕ, and B, the thing having weight, in the equal time over the distance ΓΔ. If, then, the body having weight is divided in the ratio of ΓΕ to ΓΔ, it will result that the part taken away from the body having weight is carried over the distance ΓΕ in the equal time, since the whole was carried over ΓΔ. For the speed of the smaller to that of the larger will be as the larger body to the smaller.
ἴσον ἄρα τὸ ἀβαρὲς οἰσθήσεται σῶμα καὶ τὸ βάρος ἔχον ἐν τῷ αὐτῷ χρόνῳ.
Therefore, the weightless body and the body having weight will be carried over an equal distance in the same time.
τοῦτο δʼ ἀδύνατον· ὥστʼ ἐπεὶ παντὸς τοῦ προστεθέντος μεῖζον κινήσεται διάστημα τὸ ἀβαρές, ἄπειρον ἄν φέροιτο.
But this is impossible; so that, since the weightless thing will move a greater distance than any addition, it would be carried to infinity.
φανερὸν οὖν ὅτι ἀνάγκη πᾶν σῶμα βάρος ἔχειν ἢ κουφότητα διωρισμένον.
It is manifest, therefore, that every body must necessarily have a definite weight or lightness.
ἐπεὶ δὲ φύσις μέν ἐστιν ἡ ἐν αὐτῷ ὑπάρχουσα κινήσεως ἀρχή, δύναμις δʼ ἡ ἐν ἄλλῳ ᾗ ἄλλο, κίνησις δὲ ἡ μὲν κατὰ φύσιν ἡ δὲ βίαιος πᾶσα, τὴν μὲν κατὰ φύσιν, οἷον τῷ λίθῳ τήν κάτω, θᾶττον ποιήσει τὸ κατὰ δύναμιν, τὴν δὲ παρὰ φύσιν ὅλως αὐτή.
And since nature is an inherent principle of motion, and power is a principle in another or qua other, while motion is all either according to nature or by force, that which is according to power will make the motion according to nature (such as downward motion for a stone) faster, but it will cause the motion contrary to nature entirely by itself.
πρὸς ἀμφότερα δὲ ὥσπερ ὀργάνῳ χρῆται τῷ ἀέρι· πέφυκε γὰρ οὗτος καὶ κοῦφος εἶναι καὶ βαρύς.
And for both motions, it uses air as an instrument; for this is naturally both light and heavy.
τὴν μὲν οὖν ἄνω ποιήσει φορὰν ᾗ κοῦφος, ὅταν ὠσθῇ καὶ λάβῃ τὴν ἀρχὴν ἀπὸ τῆς δυνάμεως, τὴν δὲ κάτω πάλιν ᾗ βαρύς· ὥσπερ γὰρ ἐναφάψασα παραδίδωσιν ἑκατέρῳ.
Thus, it will produce the upward movement in so far as it is light, when it is pushed and receives the beginning from the power, and the downward movement again in so far as it is heavy; for as if by clinging to it, it delivers to each.
διὸ καὶ οὐ παρακολουθοῦντος τοῦ κινήσαντος φέρεται τὸ βίᾳ κινηθέν, εἰ γὰρ μὴ τοιοῦτόν τι τὸ σῶμα ὑπῆρχεν, οὐκ ἂν ἦν ἡ βίᾳ κίνησις.
Therefore, even when the mover does not accompany it, the thing moved by force is carried; for if no such body had existed, there would have been no forced motion.
καὶ τὴν κατὰ φύσιν δʼ ἑκάστου κίνησιν συνεπουρίζει τὸν αὐτὸν τρόπον.
And it also helps forward the natural motion of each thing in the same manner.
ὅτι μὲν οὖν ἅπαν ἢ κοῦφον ἢ βαρύ, καὶ πῶς αἱ παρὰ φύσιν ἔχουσι κινήσεις, ἐκ τούτων φανερόν.
That, therefore, everything is either light or heavy, and in what manner motions contrary to nature exist, is clear from these.
ὅτι δʼ οὔτε πάντων ἐστὶ γένεσις οὔθʼ ἁπλῶς οὐθενός, δῆλον ἑκ τῶν προειρημένων· ἀδύνατον γὰρ παντὸς σώματος εἶναι γένεσιν) εἰ μὴ καὶ κενὸν εἶναί τι δυνατὸν κεχωρισμένον·
But that there is neither generation of all things nor simply of nothing, is clear from what has been said; for it is impossible that there is generation of every body, unless it is also possible for some separate void to exist.
ἐν ᾧ γὰρ ἔσται τόπῳ τὸ νῦν γινόμενον, εἰ ἐγίνετο, ἐν τούτῳ πρότερον τὸ κενὸν ἀναγκαῖον εἶναι σώματος μηθενὸς ὄντος.
For in the place where the thing now being generated will be, if it were to be generated, before this there must necessarily be a void, since no body is there.
ἄλλο μὲν γὰρ ἐξ ἄλλου σῶμα γίγνεσθαι δυνατόν, οἷον ἐξ ἀέρος πῦρ, ὅλως δʼ ἐκ μηδενὸς ἄλλου προϋπάρχοντος μεγέθους ἀδύνατον· μάλιστα μὲν γὰρ ἐκ δυνάμει τινὸς ὄντος σώματος ἐνεργείᾳ γένοιτʼ ἂν σῶμα.
For it is possible for one body to come to be out of another, for instance fire out of air, but it is impossible for it to come to be simply out of no other pre-existing magnitude; for a body would most of all come to be in actuality from something that is a body in potentiality.
ἀλλʼ εἰ τὸ δυνάμει ὂν σῶμα μηθέν ἐστιν ἄλλο σῶμα ἐνεργείᾳ πρότερον, κενὸν ἔσται κεχωρισμένον.
But if the body in potentiality is previously no other body in actuality, there will be a separate void.