§55 ὅσοις μὲν οὖν τὸ ἄνω καὶ τὸ ἔμπροσθεν διώρισται, καθάπερ τοῖς ἀνθρώποις καὶ τοῖς ὄρνισι, ταῦτα μὲν δίποδα. (τῶν δὲ τεττάρων τὰ δύο σημεῖα τοῖς μὲν πτέρυγες τοῖς δὲ χεῖρες καὶ βραχίονές εἰσιν), ὅσα δʼ ἐπὶ τὸ αὐτὸ τὸ πρόσθεν ἔχει καὶ τὸ ἄνω, τετράποδα καὶ πολύποδα καὶ ἄποδα.
Therefore, those in which the up and the front are distinguished, just as in men and birds, these are biped. (And of the four points, two are wings for the former, and hands and arms for the latter.) While those that have the front and the up in the same direction are quadruped, polypod, and footless.
καλῶ γὰρ πόδα μέρος ἐπὶ σημείῳ πεζῷ κινητικῷ κατὰ τόπον· καὶ γὰρ τὸ ὄνομα ἐοίκασιν εἰληφέναι ἀπὸ τοῦ πέδου οἱ πόδες.
For I call a foot a part at a terrestrial point that is causative of locomotion; for indeed, feet (podes) seem to have taken their name from the ground (pedon).
ἔνια δʼ ἐπὶ τὸ αὐτὸ ἔχει τὸ πρόσθιον καὶ τὸ ὀπίσθιον, οἷον τά τε μαλάκια καὶ τὰ στρομβώδη τῶν ὀστρακοδέρμων· εἴρηται δὲ περὶ αὐτῶν πρότερον ἐν ἑτέροις.
But some have the front and the back in the same place, as for example the molluscs and the spiral-shaped shellfish; and these have been spoken of before in other works.
τριῶν δʼ ὄντων τόπων, τοῦ ἄνω καὶ μέσου καὶ κάτω, τὰ μὲν δίποδα τὸ ἄνω πρὸς τὸ τοῦ ὅλου ἄνω ἔχει, τὰ δὲ πολύποδα ἢ ἄποδα πρὸς τὸ μέσον, τὰ δὲ φυτὰ πρὸς τὸ κάτω.
And since there are three regions, the up, the middle, and the down, bipeds have the up toward the up of the whole, while polypods or footless animals have it toward the middle, and plants toward the down.
αἴτιον δʼ ὅτι τὰ μὲν ἀκίνητα, πρὸς τὴν τροφὴν δὲ τὸ ἄνω, ἡ δὲ τροφὴ ἐκ τῆς γῆς.
The cause is that the latter are motionless, and the up is toward their food, and their food is from the earth.
τὰ δὲ τετράποδα ἐπὶ τὸ μέσον καὶ τὰ πολύποδα καὶ ἄποδα διὰ τὸ μὴ ὀρθὰ εἶναι· τὰ δὲ δίποδα πρὸς τὸ ἄνω διὰ τὸ ὀρθὰ εἶναι, μάλιστα δʼ ὁ ἄνθρωπος· μάλιστα γὰρ κατὰ φύσιν ἐστὶ δίπους.
And quadrupeds, polypods, and footless animals have it toward the middle because they are not erect; while bipeds have it toward the up because they are erect, and most of all man, for he is a biped most of all according to nature.
εὐλόγως δὲ παὶ αἱ ἀρχαί εἰσιν ἀπὸ τούτων τῶν μορίων· ἡ μὲν γὰρ ἀρχὴ τίμιον, τὸ δʼ ἄνω τοῦ κάτω καὶ τὸ πρόσθεν τοῦ ὄπισθεν καὶ τὸ δεξιὸν τοῦ ἀριστεροῦ τιμιώτερον.
And it is reasonable that the principles also start from these parts; for the principle is honorable, and the up is more honorable than the down, the front than the back, and the right than the left.
καλῶς δʼ ἔχει καὶ τὸ ἀνάπαλιν λέγειν περὶ αὐτῶν, ὡς διὰ τὸ τὰς ἀρχὰς ἐν τούτοις εἶναι ταῦτα τιμιώτερα τῶν ἀντικειμένων μορίων ἐστίν.
And it is also well to say the converse about them, namely, that because the principles are in these, these parts are more honorable than the opposite parts.
§6Ὅτι μὲν οὖν ἐκ τῶν δεξιῶν ἡ τῆς κινήσεώς ἐστιν ἀρχή, 6 φανερὸν ἐκ τῶν εἰρημένων.
That the principle of movement, then, is from the right, is clear from what has been said.
ἐπεὶ δʼ ἀνάγκη παντὸς συνεχοῦς, οὗ τὸ μὲν κινεῖται τὸ δʼ ἠρεμεῖ, ὅλου δυναμένου κινεῖσθαι ἑστῶτος θατέρου, ἄμφω κινεῖται τὰς ἐναντίας κινήσεις, εἶναι τὸ κοινόν, καθʼ ὃ συνεχῆ ταῦτʼ ἐστιν ἀλλήλοις, κἀνταῦθ’ ὑπάρχειν τὴν ἀρχὴν τῆς ἑκατέρου τῶν μερῶν κινήσεως, ὁμοίως δὲ καὶ τῆς στάσεως δηλονότι, καθʼ ὅσας τῶν λεχθεισῶν ἀντιθέσεων ἰδία κίνησις ὑπάρχει τῶν ἀντικειμένων μερῶν ἑκατέρῳ, πάντα ταῦτα κοινὴν ἀρχὴν ἔχει κατὰ τὴν τῶν εἰρημένων μερῶν σύμφυσιν, λέγω δὲ τῶν τε δεξιῶν καὶ τῶν ἀριστερῶν καὶ τῶν ἄνω καὶ κάτω καὶ τῶν ἔμπροσθεν καὶ τῶν ὄπισθεν.
And since for every continuous thing, in which one part is moved and the other is at rest, while the whole is able to be moved when one of the two stands still, and both are moved in opposite movements, it is necessary that there be a common point at which they are continuous with each other, and that the principle of the movement of each of the parts, and clearly likewise of their rest, should exist there, in all those of the mentioned oppositions where a proper movement belongs to each of the opposite parts, all these have a common principle at the junction of the said parts, I mean of the right and the left, of the up and the down, and of the front and the back.
κατὰ μὲν οὖν τὸ ἔμπροσθεν καὶ τὸ ὄπισθεν διάληψις οὐκ ἔστι τοιαύτη περὶ τὸ κινοῦν ἑαυτό, διὰ τὸ μηθενὶ φυσικὴν ὑπάρχειν κίνησιν εἰς τὸ ὄπισθεν, μηδὲ διορισμὸν ἔχειν τὸ κινούμενον, καθʼ ὃν τὴν ἐφʼ ἑκάτερα τούτων μεταβολὴν ποιεῖται· κατὰ δὲ τὸ δεξιόν γε καὶ ἀριστερὸν καὶ τὸ ἄνω καὶ τὸ κάτω ἔστι.
Now, concerning the front and the back, there is no such distinction in that which moves itself, because for nothing is movement toward the back natural, nor does that which is moved have a distinction by which it makes change toward each of these; but concerning the right and the left, and the up and the down, there is.
διὸ τῶν ζῴων ὅσα μέρεσιν ὀργανικοῖς χρώμενα προέρχεται, τῇ μὲν τοῦ ἔμπροσθεν καὶ ὄπισθεν διαφορᾷ οὐκ ἔχει διωρισμένα ταῦτα, ταῖς δὲ λοιπαῖς, ἀμφοτέραις μέν, προτέρᾳ δὲ τῇ κατὰ τὸ δεξιὸν καὶ ἀριστερὸν διοριζούσῃ, διὰ τὸ τὴν μὲν ἐν τοῖς δυσὶν εὐθέως ἀναγκαῖον εἶναι ὑπάρχειν, τὴν δʼ ἐν τοῖς τέτταρσι πρώτοις.
Therefore, of animals, those that proceed by using organic parts do not have these distinguished by the difference of front and back, but they do by the remaining differences, indeed by both, but first by the one that distinguishes according to the right and the left, because the one is necessarily present immediately in two, while the other is in the first four.
ἐπεὶ οὖν τό τε ἄνω καὶ τὸ κάτω καὶ τὸ δεξιὸν καὶ ἀριστερὸν τῇ αὐτῇ ἀρχῇ καὶ κοινῇ συνήρτηται πρὸς αὐτά (λέγω δὲ ταύτην τὴν τῆς κινήσεως κυρίαν), δεῖ δʼ ἐν ἅπαντι τῷ μέλλοντι κατὰ τρόπον ποιεῖσθαι τὴν ἀφʼ ἑκάστου κίνησιν ὡρίσθαι πως καὶ τετάχθαι ταῖς ἀποστάσεσι ταῖς πρὸς τὰς ῥηθείσας ἀρχάς (τάς τε ἀντιστοίχους καὶ τὰς συστοίχους τῶν ἐν τοῖς μέρεσι τούτοις) τὸ τῶν λεχθεισῶν κινήσεων ἀπασῶν αἴτιον, (αὕτη δʼ ἐστὶν ἀφʼ ἧς ἀρχῆς κοινῆς τῶν ἐν τῷ ζῴω ἥ τε τοῦ δεξιοῦ καὶ ἀριστεροῦ κίνησίς ἐστιν, ὁμοίως δὲ καὶ ἡ τοῦ ἄνω καὶ κάτω) ταύτην δʼ ἔχειν ἑκάστῳ παραπλησίως πρὸς
Since, then, the up and the down, and the right and the left are linked to the same common principle for them (and I mean by this that which is authoritative over movement), and since in everything that is to make its movement from each part in an orderly way, it is necessary that the cause of all the said movements should be somehow defined and ordered by its distances from the mentioned principles (both those that are coordinate and those that are corresponding among the things in these parts), (and this is the common principle in the animal from which the movement of both the right and the left starts, and likewise that of the up and the down) and it is necessary that each animal should have this in a similar way toward...