Because, you see, so to understand, manipulate, and dispose the soulless matter, that the art which is stored away in such mechanisms becomes almost like a soul to this material, in all the various ways in which it mocks movement, and figure, and voice, and so on, may be turned into a proof of there being something in man whereby he shows an innate fitness to think out within himself, through the contemplative and inventive faculties, such thoughts, and having prepared such mechanisms in theory, to put them into practice by manual skill, and exhibit in matter the product of his mind. First, for instance, he saw, by dint of thinking, that to produce any sound there is need of some wind; and then, with a view to produce wind in the mechanism, he previously ascertained by a course of reasoning and close observation of the nature of elements, that there is no vacuum at all in the world, but that the lighter is to be considered a vacuum only by comparison with the heavier; seeing that the air itself, taken as a separate subsistence, is crowded quite full. It is by an abuse of language that a jar is said to be “empty”; for when it is empty of any liquid it is none the less, even in this state, full, in the eyes of the experienced. A proof of this is that a jar when put into a pool of water is not immediately filled, but at first floats on the surface, because the air it contains helps to buoy up its rounded sides; till at last the hand of the drawer of the water forces it down to the bottom, and, when there, it takes in water by its neck; during which process it is shown not to have been empty even before the water came; for there is the spectacle of a sort of combat going on in the neck between the two elements, the water being forced by its weight into the interior, and therefore streaming in; the imprisoned air on the other hand being straitened for room by the gush of the water along the neck, and so rushing in the contrary direction; thus the water is checked by the strong current of air, and gurgles and bubbles against it. Men observed this, and devised in accordance with this property of the two elements a way of introducing air to work their mechanism20    According to an author quoted by Athenæus (iv. 75), the first organist (ὑδραύλης), or rather organ-builder, was Ctesibius of Alexandria, about b.c. 200.. They made a kind of cavity of some hard stuff, and prevented the air in it from escaping in any direction; and then introduced water into this cavity through its mouth, apportioning the quantity of water according to requirement; next they allowed an exit in the opposite direction to the air, so that it passed into a pipe placed ready to hand, and in so doing, being violently constrained by the water, became a blast; and this, playing on the structure of the pipe, produced a note. Is it not clearly proved by such visible results that there is a mind of some kind in man, something other than that which is visible, which, by virtue of an invisible thinking nature of its own, first prepares by inward invention such devices, and then, when they have been so matured, brings them to the light and exhibits them in the subservient matter? For if it were possible to ascribe such wonders, as the theory of our opponents does, to the actual constitution of the elements, we should have these mechanisms building themselves spontaneously; the bronze would not wait for the artist, to be made into the likeness of a man, but would become such by an innate force; the air would not require the pipe, to make a note, but would sound spontaneously by its own fortuitous flux and motion; and the jet of the water upwards would not be, as it now is, the result of an artificial pressure forcing it to move in an unnatural direction, but the water would rise into the mechanism of its own accord, finding in that direction a natural channel. But if none of these results are produced spontaneously by elemental force, but, on the contrary, each element is employed at will by artifice; and if artifice is a kind of movement and activity of mind, will not the very consequences of what has been urged by way of objection show us Mind as something other than the thing perceived?

_Μ. Ὅτι τοι, φησὶ, τὸ οὕτως εἰδέναι μεταχειρίζεσθαί τι καὶ διατιθέναι τὴν ἄψυχον ὕλην, ὡς τὴν ἐναποτιθεῖσαν τοῖς μηχανήμασι τέχνην μικροῦ δεῖν ἀντὶ τῆς ψυχῆς τῇ ὕλῃ γίνεσθαι, δι' ὧν κίνησίν τε καὶ ἦχον, καὶ σχήματα, καὶ τὰ τοιαῦτα καθυποκρίνεται, ἀπόδειξις ἂν εἴη τοῦ εἶναί τι τοιοῦτον ἐν τῷ ἀνθρώπῳ, ᾧ ταῦτα πέφυκε διὰ τῆς θεωρητικῆς καὶ ἐφευρετικῆς δυνάμεως κατανοεῖν τε ἐν ἑαυτῷ καὶ προκατασκευάζειν τῇ διανοίᾳ τὰ μηχανήματα, εἶθ' οὕτως εἰς ἐνέργειαν διὰ τῆς τέχνης ἄγειν, καὶ διὰ τῆς ὕλης δεικνύειν τὸ νόημα. Πρῶτον γὰρ ὅτι πνεύματός ἐστι χρεία πρὸς τὴν ἐκφώνησιν, κατενόησεν: εἶθ' ὅπως ἂν ἐπινοηθείη πνεῦμα τῷ μηχανήματι τῷ λογισμῷ προεξήτασε, τὴν τῶν στοιχείων φύσιν ἐπισκεψάμενος, ὅτι οὐδὲν κενὸν ἐν τοῖς οὖσίν ἐστιν, ἀλλὰ πρὸς τὸ βαρύτερον παραθέσει κενὸν τὸ κοῦφον νομίζεται, ἐπεὶ καὶ αὐτὸς ἐφ' ἑαυτοῦ κατ' ἰδίαν ὑπόστασιν μεστός τε ὁ ἀὴρ καὶ πλήρης ἐστί. Διάκενον γὰρ τὸ ἀγγεῖον ἐκ καταχρήσεως λέγεται. Ὅταν γὰρ τοῦ ὑγροῦ κενὸν ᾖ, οὐδὲν ἧττον μεστὸν ἀέρος πεπαιδευμένος καὶ τοῦτο λέγει. Σημεῖον δὲ τὸν ἐπαχθέντα τῇ λίμνῃ ἀμφορέα μὴ εὐθὺς πληροῦσθαι τοῦ ὕδατος, ἀλλ' ἐπιπολάζειν τὰ πρῶτα, τοῦ ἐναπειλημμένου ἀέρος ἐπὶ τὸ ἄνω τὸ κοῖλον ἀνέχοντος, ἕως ἂν πιεσθεὶς ὁ ἀμφορεὺς τῇ χειρὶ τοῦ ἀρυομένου ἐν τῷ βάθει γίνεται, καὶ τοῦτο δέξηται τῷ στόματι τὸ ὕδωρ: οὗ γινομένου δείκνυται τὸ μὴ κενὸν αὐτὸν εἶναι καὶ πρὸ τοῦ ὕδατος. Μάχη γάρ τις περὶ τῷ στόματι τῶν δύο στοιχείων ὁρᾶται, τοῦ μὲν ὕδατος ὑπὸ βάρους ἐπὶ τὸ κοῖλον βιαζομένου τε καὶ εἰσρέοντος, τοῦ δὲ ἀέρος τοῦ ἐναπειλημμένου τῷ κοίλῳ διὰ τοῦ αὐτοῦ στόματος ἐπὶ τὸ ἔμπαλιν συνθλιβομένου περὶ τὸ ὕδωρ, καὶ ἀναῤῥέοντος, ὡς καὶ ἀνακόπτεσθαι διὰ τούτου καὶ ἀνακοχλάζειν τὸ ὕδωρ περιαφρίζον τῇ βίᾳ τοῦ πνεύματος. Ταῦτα οὖν κατενόησε, καὶ ὅπως ἂν ἐντεθείη πνεῦμα τῷ μηχανήματι διὰ τῆς τῶν στοιχείων φύσεως ἐπενόησε. Κοῖλον γάρ τι ἐκ στεγανῆς ὕλης κατασκευάσας, καὶ πανταχόθεν τὸν ἐν αὐτῷ ἀέρα περισχὼν ἀδιάπνευστον, ἐπάγει τὸ ὕδωρ διὰ στόματος τῷ κοίλῳ, κατὰ τὸ μέτρον τῆς χρείας τὸ ποσὸν συμμετρήσας τοῦ ὕδατος, εἶθ' οὕτως ἐπὶ τὸν παρακείμενον αὐλὸν δίδωσι κατὰ τὸ ἀντικείμενον τῷ ἀέρι τὴν δίοδον, ἐκθλιβόμενος δὲ τῷ ὕδατι βιαιότερον ὁ ἀὴρ πνεῦμα γίνεται: ὅπερ ἐκπίπτον τῇ κατασκευῇ τοῦ αὐλοῦ τὸν ἦχον ποιεῖ.
Ἆρ' οὐ φανερῶς δείκνυται διὰ τῶν φαινομένων, ὅτι ἔστι τις ἐν τῷ ἀνθρώπῳ νοῦς ἄλλο τι παρὰ τὸ φαινόμενον, ὁ τῷ ἀειδεῖ τε καὶ νοερῷ τῆς ἰδίας φύσεως ταῦτα ἐν ἑαυτῷ προκατασκευάζων ταῖς ἐπινοίαις, εἶθ' οὕτως διὰ τῆς ὑλικῆς ὑπηρεσίας εἰς τὸ ἐμφανὲς ἄγων τὴν ἔνδον συστᾶσαν διάνοιαν; Εἰ γὰρ ἦν κατὰ τὸν ἀντιτεθέντα λόγον ἡμῖν τῇ φύσει τῶν στοιχείων τὰς τοιαύτας θαυματοποιίας λογίζεσθαι, αὐτομάτως ἂν ἡμῖν συνέστη πάντως τὰ μηχανήματα: καὶ οὔτε ὁ χαλκὸς τὴν τέχνην ἀνέμενεν εἰς τὸ γενέσθαι ἀνδροείκελον, ἀλλ' εὐθὺ ἂν τοιοῦτος ἐκ φύσεως ἦν: οὐδ' ἂν τοῦ αὐλοῦ πρὸς τὸν ἦχον ὁ ἀὴρ ἐδεήθη, ἀλλὰ πάντοτε ἂν ἐφ' ἑαυτοῦ ἤχει κατὰ τὸ συμβᾶν, ῥέων τε καὶ κινούμενος: τοῦ τε ὕδατος οὐκ ἂν ἦν βεβιασμένη διὰ σωλῆνος, ἡ πρὸς τὴν ἀναφορὰν τῆς τέχνης ἐκ πιεσμάτων εἰς τὸ παρὰ φύσιν ἀναθλιβούσης τὴν κίνησιν: ἀλλ' αὐτομάτως ἀνίη τὸ ὕδωρ πάντως πρὸς τὸ μηχάνημα, τῇ ἰδίᾳ φύσει ἐπὶ τὸ ἄνω ὀχετηγούμενον. Εἰ δὲ τούτων κατὰ τὸ αὐτόματόν ἐστιν οὐδὲν ὑπὸ τῆς τῶν στοιχείων φύσεως ἐνεργούμενον, ἀλλὰ τέχνῃ πρὸς τὸ δοκοῦν ἕκαστον ἄγεται: ἡ δὲ τέχνη διάνοιά τίς ἐστι ποία κίνησίς τε καὶ ἐνέργεια, ἄρα καὶ διὰ τῶν ἀντιθέτων ἡμῖν τὸ ἄλλο τι παρὰ τὸ φαινόμενον εἶναι τὸν νοῦν ἡ ἀκολουθία τῶν εἰρημένων ἀπέδειξεν.