§2#1Ζητητέον οὖν, ὅπῃ τῶν λόγων ὁ ἕτερος παραλογίζεται, κάνονα τῆς κρίσεως ποιησαμένοις ἡμῖν τὴν χρείαν τῆς ἀναπνοῆς, ἣν ἐδείξαμεν ἐν τοῖς περὶ αὐτῆς λόγοις διττὴν οὖσαν, ὡς ἐδόκει καὶ Ἱπποκράτει· τὴν μὲν γὰρ ἑτέραν, τὴν μείζω, φυλακὴν τῆς ἐμφύτου θερμασίας, τὴν δὲ ἑτέραν, τὴν ἐλάττονα, θρέψιν τοῦ ψυχικοῦ πνεύματος.
Therefore, we must investigate in what way one of the arguments is fallacious, making the use of respiration our standard of judgment, which we showed to be twofold in our discussions concerning it, as it also seemed to Hippocrates; for the one, the greater, is the preservation of the innate heat, while the other, the lesser, is the nourishment of the psychic pneuma.
ἀλλ’ εἰς ἄμφω ταῦτα παρὰ τῆς διὰ τῶν ῥινῶν εἰσπνοῆς ὠφελεῖσθαι τὸν ἐγκέφαλον ἐλέγομεν.
But we were saying that for both of these the brain receives benefit from the inhalation through the nostrils.
ὥστ’ οὐδὲν θαυμαστὸν, ὀλίγης αὐτῷ παρὰ καρδίας χορηγουμένης τῆς ἐπικουρίας, ὀλίγην εἶναι καὶ τὴν βλάβην, τῶν καρωτίδων λεγομένων ἀρτηριῶν βρόχοις διαληφθεισῶν.
Consequently, it is not at all surprising that, since the assistance supplied to it from the heart is small, the harm is also small when the so-called carotid arteries are constricted with ligatures.
ἀλλ’ ἴσως τις φήσει, μηδ’ ἐλαχίστην φαίνεσθαι· δι’ ὅλης γὰρ ἡμέρας τὸ ζῶον, ὡς ἐπειράθημεν πολλάκις, ἀβλαβὲς διαμένει.
But perhaps someone will say that not even the slightest harm appears; for during a whole day the animal, as we have often tested, remains unharmed.
καὶ ὀρθῶς γε φήσει.
And indeed he will speak correctly.
καὶ δὴ τοῦθ’ ἡμεῖς ἀποροῦντες ἐπενοήσαμεν τοιούτου τινὸς ἀποπειραθῆναι φαινομένου.
So we, being perplexed by this, conceived the idea of testing some such phenomenon.
πρότερον δ’ ἐρῶ τὸν λογισμὸν, ὅθεν εἰς τοῦθ’ ἥκομεν.
But first I will state the reasoning from which we came to this.
ἐπεὶ γὰρ ἐν ἑτέροις ἡμῖν ἀποδέδεικται, τὰς κατὰ τὸν ἐγκέφαλον κοιλίας πνεύματος εἶναι ψυχικοῦ μεστὰς, τροφῆς χρήζοντος συνεχοῦς, ἀποδέδεικται δὲ καὶ ὡς δαπανᾶται τοῦτο ἐν ταῖς καθ’ ὁρμὴν κινήσεσιν, ἄμεινον ἐδόκει τρέχειν ἀναγκάζειν τὸ ζῶον, ᾧ τὰς ἀρτηρίας βρόχοις διελάβομεν.
For since it has been demonstrated by us in other works that the ventricles of the brain are full of psychic pneuma, which stands in need of continuous nourishment, and it has also been demonstrated that this is consumed in voluntary motions, it seemed better to compel the animal whose arteries we had constricted with ligatures to run.
ἐπεὶ δὲ μέχρι μὲν πολλοῦ καλῶς ἔτρεχε, μέχρι παντὸς δ’ οὐκ ἠδύνατο, ζητεῖν ἐδόκει χρῆναι, διότι μέχρι μὲν πολλοῦ ἔτρεχε, μέχρι παντὸς δὲ οὐκ ἠδύνατο, καὶ πάλιν αὐτὸ μέχρι πολλοῦ οὐ διαρκεῖν, ἀλλ’ εὐθέως ἐκλύεσθαι, δαπανωμένου τοῦ ψυχικοῦ πνεύματος.
But since it ran well for a long time, but was not able to do so indefinitely, it seemed necessary to investigate why it ran for a long time but was not able to do so indefinitely, and again why it does not hold out for a long time but is immediately exhausted when the psychic pneuma is consumed.
ἀλλὰ καὶ αὐτοῦ τούτου τὸ δικτυοειδὲς πλέγμα πρὸς τῶν ἀμφὶ τὸν Ἡρόφιλον κληθὲν ἐδόκει τὴν αἰτίαν ἔχειν.
But indeed, the retiform plexus, so called by those around Herophilus, seemed to contain the cause of this very thing.
ἐκεῖ γὰρ αἱ ἐπὶ τὸν ἐγκέφαλον ἀνιοῦσαι καρωτίδες ἀρτηρίαι, πρὶν διελθεῖν τὴν σκληρὰν μήνιγγα, σχίζονται πολυειδῶς ὑπ’ αὐτῆς, περιπλεκόμεναι κατὰ πολλοὺς στίχους, ὡς εἰ νοήσαις ἀλλήλοις ἐπικείμενα δίκτυα πλείω, καὶ χώραν παμπόλλην, ἣν καλοῦσιν ἐγκεφάλου βάσιν, καταλαμβάνουσιν, ἐνὸν αὐταῖς εὐθὺς μὲν διεκπεσεῖν τὰς μήνιγγας, ἐμφῦναι δὲ εἰς τὸν ἐγκέφαλον, οὗ περ ἐξ ἀρχῆς ἰέναι.
For there the carotid arteries ascending to the brain, before passing through the dura mater, are split in many ways by it, being intertwined in many layers, as if you were to conceive of several nets lying upon one another, and they occupy a very large area which they call the base of the brain, although it was possible for them to pass immediately through the membranes and enter into the brain itself, where they were originally going.
τοῦθ’ οὖν τὸ θαυμαστὸν πλέγμα πρὸς τῆς μηδὲν εἰκῆ ποιούσης φύσεως ἐν οὕτως ἀσφαλεῖ χώρᾳ ταχθῆναι, μεγάλης τινὸς ἐδόκει χρείας ἐνδεικτικὸν ὑπάρχειν.
Therefore, that this wonderful plexus was arranged in such a secure place by nature, which does nothing in vain, seemed to be indicative of some great use.
ἀλλ’ ἐπειδὴ τὴν τῶν ἐντέρων ἕλικα καὶ τὴν τῶν εἰς τοὺς ὄρχεις ἐμφυομένων ἀγγείων ἀκριβοῦς τε πέψεως ἕνεκα τῶν περιεχομένων ὑλῶν καὶ προσέτι δαψιλοῦς παρασκευῆς ταῖς ἑξῆς ἐνεργείαις ἑωρῶμεν γεγενημένην, εὔλογον ἐδόκει κᾀνταῦθα τοιοῦτόν τι μεμηχανῆσθαι τὴν φύσιν, ἅμα τε κατεργαζομένην πολλῷ χρόνῳ τὴν ἐν ταῖς ἀρτηρίαις ὕλην, αἷμα θερμὸν καὶ λεπτὸν καὶ ἀτμῶδες ὑπάρχουσαν, ἅμα τε κατασκευάζουσαν τροφὴν δαψιλῆ τῷ κατὰ τὸν ἐγκέφαλον ψυχικῷ πνεύματι.
But since we saw that the winding of the intestines and that of the vessels entering the testes had come to be for the sake of the precise concoction of the contained materials and, moreover, for the abundant preparation for the subsequent activities, it seemed reasonable that here too nature had devised some such thing, at once processing over a long time the material in the arteries, which is warm, thin, and vaporous blood, and at the same time preparing abundant nourishment for the psychic pneuma in the brain.
καὶ διὰ τοῦτο, κᾂν στερηθῇ τῆς πρὸς τὴν καρδίαν συνεχείας ὁ ἐγκέφαλος, ἐξαρκεῖ αὐτῷ τὸ δικτυοειδὲς πλέγμα μέχρι πολλοῦ, καὶ μάλισθ’ ὅταν ἀτρεμῇ τὸ ζῶον, ὡς ἂν μὴ δαπανωμένου τηνικαῦτα τοῦ ψυχικοῦ πνεύματος εἰς τὴν καθ’ ὁρμὴν ἐνέργειαν.
And for this reason, even if the brain is deprived of its continuity with the heart, the retiform plexus suffices for it for a long time, and especially when the animal is at rest, as the psychic pneuma is not consumed at that time for voluntary activity.
τὸ μὲν δὴ χαλεπώτατόν τε καὶ ἀπορώτατον δοκοῦν, τὸ κατὰ τὰς καρωτίδας ἀρτηρίας, οὐδὲν ἔχειν ἄπορον ἔτι φαίνεται.
Thus the problem concerning the carotid arteries, which seemed most difficult and perplexing, no longer appears to have any difficulty.
παραπλησίως δ’ αὐτῷ καὶ τὸ κατὰ τὰς ἄλλας ἁπάσας, ὧν ἑκάστης βρόχῳ διαληφθείσης οὐδὲν ἐν τῷ παραυτίκα βλάπτεται τὸ μέρος.
And similarly to it, the problem concerning all the others, each of which, when constricted with a ligature, causes no harm to the part for the moment.