I was recently moving to a new city, and I had promised myself that before I did I would finish a chapter I owed for a book (very late). This is basically the conversation that was going on in my head (I’m both people in this story):

“You asked me, Apollonius, best of Asclepiads, to give you a written version of my recent class lectures on fevers. That way, if you wanted to do some studying on fevers, you would have as it were a reminder of my lesson, especially now that I’ve decided to go abroad and will be far away from you, and you might not find anyone else who would so eagerly explain to you the secrets of medicine. I’m happy to do what you ask. In fact, I was prepared to produce a lesson for you had you asked for one, both lecture and notes, and not only on fevers, but on any other medical subject—just not now, when the other things I have to do before my trip are stressing me out and making it impossible to work on these kinds of things. But I would have done it before, namely when it was possible and I had time to write up the theory after your requested it. The study of fevers is, as you know, complex and difficult to study. Lots of time is required to get a hold on it and to write it down. And you agree that the work must be worthy of both you and me, otherwise it would be pointless for me to choose to write it up and you to choose to read it.

“In fact, in the end I had let go of the idea of doing it for these reasons, except that a certain saying of ancient men—a nice one—occurred to me and persuaded me that ‘one must do right by one’s friends, even if one must debase one’s art to meet their demands, and not hold back from this very thing.’ It then seemed right to me to put the present book together as a kind of introduction, and since I promise there will be another book on the whole theory of fevers at a suitable time later on, I offer you a reminder of true friendship by means of this discussion as deposit. And so let us comply with your request and say whatever the time allows us to say, not using the breadth of the art and our facility in discourse (if ever it existed), but making use rather of the brief time we have. But let’s be lenient with one another: you for <not> already asking me ages ago when it would have been easier to receive not an introduction but a long book on fevers; and me for not ever wanting to go against friends in any way.”

ἤιτησας ἡμᾶς, Ἀσκληπιαδῶν ἄριστε, Ἀπολλώνιε, περὶ πυρετῶν σοι τοσαῦτα διὰ γραφῆς παραδοῦναι, ὅσα σχεδὸν πὰρ ἡμῖν φοιτῶντι διὰ γλώττης παρεδηλώσαμεν, ἵν' ὥσπερ ὑπόμνημα τῆς ἡμῶν εἴη σοι διδασκαλίας, βουλομένῳ περὶ πυρετῶν θεωρεῖν, καὶ μάλιστα νυνί, ὅτε καὶ ἀποδημεῖν ἡμεῖς ἐβουλευσάμεθα, καὶ μακρὰν ἀφ' ὑμῶν γενέσθαι, σὺ δὲ οὐκέτ' ἴσως ἕξεις τὸν οὕτω σοι προθύμως τὰ τῆς ἰατρικῆς διασαφήσοντα ὄργια. ἐγὼ μὲν οὖν ἕπεσθαί σοι ῥᾴδιος, ἐφ' ἃ κελεύεις αὐτός. καὶ μὴ ὅτι περὶ πυρετῶν, ἀλλὰ καὶ περὶ παντὸς ἄλλου θεωρήματος ἰατρικοῦ ἕτοιμος ἂν ἦν, σοῦ χάριν καὶ γλώττῃ καὶ γράμμασι διδασκαλίαν ποιήσασθαι, εἴγε μὴ νῦν, ὅτε πρὸς ἀλλ' ἄττα, τῆς ἐξόδου βιαζομένης, ἡμεῖς ἐπειγόμεθα, μὴ συγχωροῦντα τὴν περὶ τὰ τοιαῦτα σπουδήν, ἀλλὰ πρὸ καιροῦ, ὅτε δηλονότι οἷόν τε ἦν καὶ χρόνον ἡμῖν ἐγγενέσθαι μετὰ τὴν αἴτησιν πρὸς τὴν τοῦ θεωρήματος ξυγγραφήν, τὸ περὶ τούτων ὤφθης αἰτούμενος. πολυσχιδὴς γάρ, ὡς οἶδας, καὶ δυσθεώρητος ἡ περὶ πυρετῶν θεωρία καὶ πολλοῦ δεομένη χρόνου πρὸς κατάληψίν τε καὶ ξυγγραφήν· δεῖν δὲ καὶ αὐτὸς ἂν ξυμφαίης σαυτοῦ τε καὶ ἡμῶν αὐτῶν ἄξιον εἶναι τὸ σπουδαζόμενον, εἰ μὴ μάτην αὐτὸς μὲν γράφειν, σὺ δὲ ἀναγινώσκειν αἱρούμεθα.

καὶ εἴασα ἂν τελέως τοὐγχείρημα διὰ ταῦτα, εἰ μή τις λόγος παλαιῶν ἀνδρῶν καὶ καλῶς ἔχων ἐπῆλθε πείθων με, ὡς ἀνάγκη φιλίαις εἴκειν, κἂν δέῃ συγκατιέναι τὴν τέχνην, ἐπὶ ταῖς ἀξιώσεσι, μηδ' αὐτοῦ δὴ τούτου γε φείδεσθαι. ἀμέλει καὶ ἔδοξέ μοι, ὥσπερ ἐν εἰσαγωγῆς τρόπῳ, τὸ παρὸν συντάξασθαι σύγγραμμα, καὶ ἄλλο ἐπαγγελλόμενον περὶ τῆς ὅλης τῶν πυρετῶν θεωρίας, ἐν ἁρμόζοντι δῆθεν ἐσόμενον χρόνῳ, νυνὶ τουτί σοι ὡς ἐν ὑποθήκης ἐκδοῦναι λόγῳ, ἀκριβοῦς φιλίας ὑπόμνημα. καὶ δὴ λέγωμέν σοι πειθόμενοι, ἃ ἂν ὁ καιρὸς διδῷ, μὴ τῷ τῆς τέχνης πλάτει, καὶ τῇ ἡμετέρᾳ περὶ τὸ λέγειν, εἴ τίς ἐστιν, εὐπορίᾳ, τοῦ χρόνου δὲ μᾶλλον χρησάμενοι τῇ βραχύτητι. ἀμφοτέροις δὲ παρ' ἀμφοτέρων ἔσται συγγνώμη, σοὶ μὲν ἤδη πάλαι αἰτήσαντι, ὅτε μὴ εἰσαγωγήν, ἀλλὰ βίβλον μακρὰν <περὶ> πυρετῶν εἰληφέναι ῥᾴδιον ἦν, ἐμοὶ δὲ φίλοις ἐφ' ὁποιῳδηποτοῦν οὐκ ἀντιβαίνειν ἐθέλοντι.

Pseudo-Alexander of Aphrodisias, Fevers 1, 81–82 Ideler =1,1–2,12 Tassinari

Why doesn't oil combine together with other liquids?

Because, since it is viscous and dense and unified and not cut up into fine parts like other liquids, it does not have space for another liquid to move into it and combine with it.

Some things that are joined, however, are joined with one another by mixture, like the qualities of the elements. They have primary qualities that are completely concealed and that produce other [qualities], but are able to be separated and liberated by nature once again. Honey-wine and sour-wine imitate nature, since to our perception they seem to exist as a mixture. In truth, however, and with respect to their substantial nature, they are not like the elements.

Other things are joined by juxtaposition, like water and oil; still others are joined by combination, like barley with wheat; others by cementing, like stone with stone; others by adhesion and similar processes, like blood with flesh or marrow or bone; others by nailing, like wood to wood because some nails were fitted between them; others, by attachment and weaving together, like links in a chain.

But in the case of ensouled things, as in the case of wrestlers*, the soul is not joined with the body in any these ways. That would be too absurd. Instead, the soul joins the body through a kind of suitable medium, which is to some extent receptive of the nature of both. And it [sc. the medium] embraces both a created and contrived thing and combines the incorporeal with the corporeal, the immortal with the corruptible, the pure with the impure, the divine with the earthly, as the discussion will show.

For when the blood is concocted in the liver and changed by the localized balanced proportion of heat and moisture, it generates a vapory pneuma. When this rises with the blood through the hollow-vein towards the heart, as it is heated and refined more, it [sc. the pneuma] becomes air-like. And again, when it is sent up through the carotid artery towards the base of the brain, being guided there by nature’s providence, casting off the immoderate boiling in accordance with a certain peculiar natural quality accompanying the coldness of the brain, the pneuma becomes aitherial, which is the soul’s instrument for activity.

So, just as wild horses are chastened by a bridle, so this [pneuma] is bridled by a certain irrational natural capacity. Furthermore, it is indeed through respiration that the air that has come into the heart is refined and goes up through the arteries towards the head, and it is made nourishment of the aetherial and psychic pneuma. If [the air] meets a body, let it strengthen the body; but if it meets finest, purest, most radiant [pneuma], then [let it strengthen] the rational soul, being somehow a corporeal incorporeal, an intermediate bound between extremes of contrary substance.

When this pneuma is properly stable, in everything it does, it manages, with the soul, to act rationally [κατὰ λόγον]. But when it is cooled immoderately and compressed and thickened, it becomes unsuitable for the intense activity of the soul [and] makes the activities idle and sluggish. When it has been cooled and thickened extremely immoderately, the generated body also causes the soul to depart due to the unsuitability of the substance, as in the case of lethargy, torpor and a draught of cold poison. On the other hand, when it is heated immoderately and is moved more than is needed, it causes the soul to act immoderately in accordance with the soul’s displacement [κατὰ τὰς ἐκστάσεις τῆς ψυχῆς] in [cases of] phrenitis. When this affection becomes even stronger, after it is exhausted, it will make the soul depart again by not preserving their being bound together.

Consider with me a different work of god. For since it was fated that it [sc. the soul] be confined from the heavenly and divine body to an earthly body, [the god] contrived the descent in shape, structure and colour. For the head itself it formed into a sphere, just like a little heaven. It arranged the brain—bright and without excess, having given seven passages to it representing the number of the movers of the stars—to rise above the whole body. For heaven, too, rises above everything in the world of coming to be and passing away.

*the image is of two people embracing and holding on to one another.

Διὰ τί τὸ ἔλαιον οὐδενὶ τῶν ὑγρῶν ἀναμίγνυται;

ὅτι γλίσχρον ὂν καὶ παχυμερὲς καὶ ἡνωμένον καὶ μὴ τεμνόμενον εἰς λεπτὰ μόρια καθάπερ τὰ ἄλλα ὑγρά, οὐ δίδωσιν χώραν ἑτέρῳ ὑγρῷ ἐγκαταβληθῆναι εἰς αὐτὸ καὶ ἀναμιχθῆναι αὐτῷ·

τὰ δὲ ὁμιλοῦντα ἑαυτοῖς ὁμιλεῖ τῶν κατὰ τὴν κρᾶσιν, ὡς αἱ ποιότητες τῶν στοιχείων παντελῶς ἔχουσαι τὰς πρώτας ποιότητας ἀφανιζομένας καὶ ἑτέρας γεννωμένας, δυναμένας δὲ πάλιν ὑπὸ φύσεως χωρισθῆναι καὶ σωθῆναι. τὸ δὲ μελίκρατον καὶ τὸ ὀξύκρατον μιμεῖται τὴν φύσιν, τῇ αἰσθήσει μὲν νομιζόμενα κατὰ κρᾶσιν, εἶναι μὴ ὄντα δὲ κατὰ ἀλήθειαν· καὶ πρὸς τὴν φύσιν οὐσιωδῶς, ὥσπερ τὰ στοιχεῖα.

τὰ δὲ κατὰ παράθεσιν, ὡς ὑδρέλαιον· τὰ δὲ κατὰ μῖξιν, ὡς κριθὴ πυροῖς· τὰ δὲ κατὰ κόλλησιν, ὡς λίθος λίθῳ· τὰ δὲ κατὰ πρόσφυσιν καὶ ὁμοίως, ὡς αἷμα σαρκὶ ἢ μυελῷ ἢ ὀστῷ. τὰ δὲ κατὰ γόμφωσιν, ὡς ξύλον ξύλῳ διὰ γόμφων τινῶν ἐν μέσῳ βαλλομένων. τὰ δὲ κατὰ ἀντοχὴν ἑαυτῶν καὶ περιπλοκήν, ὡς κρίκος κρίκῳ.

ἐπὶ δὲ ἐμψύχων, ὡς ἐπὶ παλαιόντων, κατ' οὐδένα τούτων τῶν τρόπων μίγνυται ἡ ψυχὴ σώματι. διὰ τὸ πολλὴν ἐπάγεσθαι ἀτοπίαν [mss. ἀντοπίαν], ἀλλὰ μᾶλλον κατ' ἐπιτηδειότητα ὁμιλεῖ σώματι ψυχὴ διὰ μέσου τινός, ὅπερ ἀμφοτέρων ἀναδεχόμενον φύσιν ποσῶς· καὶ προσφιλεῖ γινόμενον καὶ σοφιζόμενον, ἀμφότερον μίγνυσι τὸ ἀσώματον τῷ σώματι, τὸ ἀθάνατον τῷ φθαρτῷ, τὸ καθαρὸν τῷ ἀκαθάρτῳ, τὸ θεῖον τῷ γηΐνῳ, ὡς ὁ λόγος δείξει·

ἐν γὰρ τῷ ἥπατι τοῦ αἵματος πεττομένου καὶ μεταβαλλομένου ὑπὸ τῆς αὐτόθι συμμέτρου θερμότητος καὶ ὑγρότητος, γεννᾶται πνεῦμαἀτμοειδές· τοῦτο δὲ διὰ τῆς κοίλης φλεβὸς ἀνιὸν μετὰ τοῦ αἵματος πρὸς καρδίαν, καὶ ἐπὶ πλέον θερμαινόμενον καὶ λεπτυνόμενον, γίνεται ἀεροειδές· καὶ πάλιν ἀναπεμπόμενον διὰ τῶν καρωτίδων ἀρτηριῶν πρὸς τὴν βάσιν τοῦ ἐγκεφάλου κατὰ πρόνοιαν φύσεως ἐκεῖσε παιδαγωγούμενον κατ' ἰδιότητά τινα φυσικὴν ὑπὸ τῆς τοῦ ἐγκεφάλου ψυχρότητος ἀποβαλὸν τὴν ἄμετρον ζέσιν, γίνεται πνεῦμα αἰθεροειδές, ὅπερ ὄργανόν ἐστι ψυχῆς πρὸς ἐνέργειαν·

ὥσπερ ἄγριος ἵππος ὑπὸ χαλινοῦ σωφρονιζόμενος, οὕτω δὲ τοῦτο χαλιναγωγούμενον ὑπό τινος ἀρρήτου φυσικῆς δυνάμεως· ἔτι γε μὴν διὰ τῆς ἀναπνοῆς ὁ εἰσιὼν ἀὴρ ἐν τῇ καρδίᾳ λεπτυνόμενος καὶ ἀνιὼν διὰ τῶν ἀρτηριῶν πρὸς ἐγκέφαλον, καὶ αὐτὸ τροφὴ καθίσταται τοῦ αἰθεροειδοῦς καὶ ψυχικοῦ πνεύματος· ὅπερ εἰ μὲν σῶμα τυγχάνει, προσωκείτω τῷ σώματι, εἰ δὲ λεπτότατον καὶ καθαρότατον καὶ διαυγέστατον φιλιοῦται, ψυχῇ λογικῇ σῶμα ἀσώματόν πως ὑπάρχον καὶ δεσμὸς ἔμμεσος τυγχάνει τῶν ἄκρων ἐναντίαν οὐσίαν ἐχόντων·

τοῦτο τὸ πνεῦμα καλῶς μὲν εὐσταθοῦν διάγει ψυχῇ πάντα κατὰ λόγον ἐνεργεῖν· ἀμέτρως δὲ ψυχόμενον καὶ πιλούμενον καὶ παχυνόμενον καὶ ἀνεπιτήδειον γινόμενον πρὸς ἐνέργειαν σύντονον ψυχῆς ποιεῖ τὰς πράξεις ἀργοτέρας καὶ νωθροτέρας· ἀμετρότατα δὲ ψυχθὲν καὶ παχυνθὲν καὶ σῶμα γενόμενον παρασκευάζει ταύτην ἀφίστασθαι διὰ τὸ ἀνεπιτήδειον τῆς οὐσίας, ὡς ἐπὶ ληθάργων καὶ κάρων καὶ πόσεως ψυχρῶν δηλητηρίων· πάλιν δὲ θερμανθὲν ἀμέτρως καὶ πλέον τοῦ δέοντος κινούμενον, παρασκευάζει ψυχὴν ἀμετρότερον ἐνεργεῖν κατὰ τὰς ἐκστάσεις τῆς ψυχῆς ταῖς φρενίτισιν· ἔτι δὲ πλέον τοῦτο παθὸν καὶ ἐκδαπανηθὲν ποιήσει πάλιν ψυχὴν ἀφίστασθαι τῷ μὴ εὐπορεῖν τοῦ δεσμοῦντος ἀμφότερα.

θεώρει δέ μοι ἕτερον ἔργον θεοῦ· ἐπειδὴ γὰρ ταύτην ἔμελλεν ἀπὸ σώματος οὐρανίου καὶ θείου κατακλείειν σώματι γηΐνῳ, σοφίζεται τὴν κάθοδον σχήματι, κατασκευῇ, χρώματι. αὐτὴν μὲν γὰρ τὴν κεφαλὴν σφαιροειδῆ διετύπωσε, καθάπερ μικρὸν οὐρανόν· τὸν δὲ ἐγκέφαλον λαμπρὸν καὶ ἀπέριττον ἔταξε δεδωκὼς αὐτῷ πόρους ἑπτὰ τῶν κινουμένων ἀστέρων τὸν ἀριθμὸν διατυπώσας. ὑπερέχειν δὲ τοῦ παντὸς σώματος· καὶ γὰρ ὁ οὐρανὸς ὑπερέχει πάντα τὰ ἐν γενέσει καὶ φθορᾷ.

Pseudo-Alexander, Problems, 2.67

Pseudo-Alexander wonders why his friend Apollonius didn't ask him earlier to write a book

Pseudo-Alexander on why oil doesn't mix with water, how the soul is joined to the body, and why the head is like a little heaven