Or rather, before dealing with these, it is right that we should mark the skilled workmanship of nature in the actual construction of the body. For as that which is hard and resistent does not admit the action of the senses (as we may see in the instance of our own bones, and in that of plants in the ground, where we remark indeed a certain form of life in that they grow and receive nourishment, yet the resistent character of their substance does not allow them sensation), for this reason it was necessary that some wax-like formation, so to say, should be supplied for the action of the senses, with the faculty of being impressed with the stamp of things capable of striking them, neither becoming confused by excess of moisture (for the impress would not remain in moist substance), nor resisting by extraordinary solidity (for that which is unyielding would not receive any mark from the impressions), but being in a state between softness and hardness, in order that the living being might not be destitute of the fairest of all the operations of nature-I mean the motion of sense.

Now as a soft and yielding substance, if it had no assistance from the hard parts, would certainly have, like molluscs, neither motion nor articulation, nature accordingly mingles in the body the hardness of the bones, and uniting these by close connection one to another, and knitting their joints together by means of the sinews, thus plants around them the flesh which receives sensations, furnished with a somewhat harder and more highly-strung surface than it would otherwise have had.

Μᾶλλον δὲ πρὸ τούτων ἄξιον κατανοῆσαι τὸ τεχνικὸν τῆς φύσεως ἡμῶν ἐν αὐτῇ τῇ δημιουργίᾳ τοῦ σώματος. Ἐπειδὴ γὰρ τὸ σκληρόν τε καὶ ἀντίτυπον τὰς αἰσθητικὰς ἐνεργείας οὐ καταδέχεται͵ ὡς ἔστιν ἰδεῖν ἐπί τε τῶν ἐν ἡμῖν ὀστέων καὶ τῶν ἐν τῇ γῇ φυτῶν͵ ἐν οἷς ζωῆς μέν τι κατανοοῦμεν εἶδος ἐν τῷ αὔξειν καὶ τρέφεσθαι͵ οὐ μὴν παρεδέξατο ἐναντίως ἡ ἀντιτυπία τοῦ ὑποκειμένου τὴν αἴσθησιν, τούτου χάριν ἔδει καθάπερ κηροειδῆ τινα κατασκευὴν ὑποτεθῆναι ταῖς κατ' αἴσθησιν ἐνεργείαις͵ δυναμένην τοῖς ἀντιληπτικοῖς τύποις ἐνσφραγισθῆναι͵ μήτε συγχεομένην δι' ὑπερβαλλούσης ὑγρότητος· οὐ γὰρ [244] ἂν διαμείνοι ἐν τῷ ὑγρῷ τὸ τυπούμενον, μήτε ἀντιτυποῦσαν ἐν τῇ ἀμετρίᾳ τῆς πήξεως· ἀσήμαντον γὰρ πρὸς τοὺς τύπους ἐστὶ τὸ ἀνύπεικτον· ἀλλὰ μέσως ἔχουσαν μαλακότητός τε καὶ στεῤῥότητος͵ ὡς ἂν μὴ τοῦ καλλίστου τῶν κατὰ τὴν φύσιν ἐνεργημάτων͵ τῆς αἰσθητικῆς λέγω κινήσεως͵ ἀμοιροίη τὸ ζῶον.  

Ἐπειδὴ τοίνυν τὸ μαλακόν τε καὶ εὔεικτον μηδεμίαν τὴν ἐκ τῶν στεῤῥῶν ἔχον ἐνέργειαν͵ ἀκίνητον ἂν ἦν πάντως καὶ ἀδιάρθρωτον κατὰ τοὺς θαλασσίους πνεύμονας, διὰ τοῦτο καταμίγνυσιν ἡ φύσις τῷ σώματι τὴν τῶν ὀστέων στεῤῥότητα͵ καὶ ταῦτα πρὸς ἄλληλα διὰ τῆς προσφυοῦς ἁρμονίας ἑνώσασα͵ τοῖς τε διὰ τῶν νεύρων συνδέσμοις τὰς συμβολὰς αὐτῶν ἐπισφίγξασα͵ οὕτως αὐτοῖς τὴν δεκτικὴν τῶν αἰσθήσεων περιέφυσε σάρκα͵ δυσπαθεστέραν τε καὶ εὐτονωτέραν τῇ ἐπιφανείᾳ διειλημμένην.