Mixing Body and Soul: Galen on the Substance of Soul in QAM and De Propriis Placitis

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  • 1 Department of Philosophy and Religious Studies, Utrecht University, Janskerkhof 13, 3512 BL Utrecht, The Netherlands
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In a late treatise, That the Capacities of the Soul Follow the Mixtures of the Body (QAM), Galen of Pergamum infamously offered the view that the substance of the soul is identical with a bodily mixture. This thesis has been found radical and extreme in modern scholarship and is generally considered to be at odds with Galen’s ‘agnosticism’ on the substance of soul. In this paper I propose a close reading of QAM that allows us to make sense of it in terms of Galen’s other work, including his late work On My Own Opinions (De Propriis Placitis).


In a late treatise, That the Capacities of the Soul Follow the Mixtures of the Body (QAM), Galen of Pergamum infamously offered the view that the substance of the soul is identical with a bodily mixture. This thesis has been found radical and extreme in modern scholarship and is generally considered to be at odds with Galen’s ‘agnosticism’ on the substance of soul. In this paper I propose a close reading of QAM that allows us to make sense of it in terms of Galen’s other work, including his late work On My Own Opinions (De Propriis Placitis).

Keywords: Galen; soul; mixture

1 Introduction

In his late treatise entitled That the Capacities of the Soul Follow the Mixtures of the Body (῞Οτι ταῖς τοῦ σώµατος κράσεσιν αἱ τῆς ψυχῆς δυνάµεις ἕπονται, commonly abbreviated after its Latin translation as QAM), Galen, besides arguing that psychic capacities ‘follow’ or ‘depend’ upon bodily mixtures, flirts—to say the least—with the thesis that the substance or nature of soul itself is nothing else than a specific bodily mixture. Thus, it has been noted that there are two separate theses advanced in QAM: (1) the weaker thesis described in its title, that the capacities of the soul follow the mixtures of the body; (2) the stronger thesis that we encounter in the first part of the treatise, that the substance of the soul is identical to a bodily mixture. As has been pointed out before, this stronger thesis provides us with some problems with regard to our understanding of Galen. Galen is well known for expressing his ignorance and lack of interest with regard to speculative questions, particularly the question of the substance of the soul. Why, then, would he advance such a strong reductionism or physicalism in QAM? Notably, one of the works in which Galen repeatedly claims to not know the substance of the soul, is De Propriis Placitis (Prop. Plac.), a work which is dated after QAM. Therefore, even if we were to make Galen’s speculative wanderings in QAM itself intelligible, we are still stuck with another question: why, then, did he refrain from maintaining the stronger thesis in his later work?

Confronted with these questions, previous scholarship has come up with several strategic explanations for the presence of the stronger thesis in QAM. The common assumption underlying these approaches seems to be that QAM’s bold reductionism cannot possibly be an expression of Galen’s own thoughts, both because it conflicts with his other work as well as because it is considered simply too radical or extreme in itself.1 There has been quite a bit of scholarship on QAM already, but as I hope to show in this paper, its philosophical import and relation to the rest of the Galenic corpus has not yet been adequately analysed.

What I offer in this paper is a reading that attempts to take QAM serious in its own right and that integrates its content with other Galenic works. Particularly, I will compare it with Prop. Plac. since, as one of Galen’s latest works in which he again seems to be agnostic about the substance of soul, this is the most problematic case. Building on work of previous scholars, notably Mario Vegetti and Teun Tieleman, I aim to show that what Galen has to say on the soul in QAM—classed by Galen himself among the works ‘on Platonic philosophy’ (De Libris Propriis xix. 46 Kühn)—can be seen as a continuation of his earlier work and is not necessarily at odds with his repeated avowals of ignorance with regard to the substance of the soul.2 An important aspect of this reading is the epistemological status awarded to the stronger thesis and Galen’s distinction between scientific knowledge and what is plausible (πιθανός).3

Since our focus will be on the stronger of the two theses, I shall limit my analysis of QAM to the first part of the text. I shall argue that the two theses should be understood in their interrelationship, more specifically in that the stronger thesis is proposed by Galen as the best possible proof of the weaker thesis. Following the order of the text, we shall move from (1) Galen’s introduction of the subject and delineation of his basic philosophical outlook on the soul involving tripartition, hylomorphism and the relation between the notions of capacity, activity and substance; (2) the discussion of the lower two parts of the soul in an exchange with Peripatetic philosophy; (3) the discussion of the (possibly immortal) rational part of the soul in an exchange with Platonism and the culmination of the argument in Galen’s approval—with some adaptation—of the position of the Peripatetic Andronicus of Rhodes; (4) the comparison between QAM and Prop. Plac. and the distinction between knowledge and what is plausible.

2 Galen’s Introduction of the Argument

Before Galen delves into the question of the substance of the soul, he makes some introductory remarks. He starts by stating that he has already found the weaker thesis to be true after repeated testing, both by himself and in the company of his teachers and ‘the best philosophers’. Besides being true, he has also found it to be useful, since good bodily mixture is conducive to becoming virtuous (QAM 32.9-13 Müller = iv. 768 Kühn):4

διὰ τῶν ἐδεσµάτων τε καὶ ποµάτων ἔτι τε τῶν ὁσηµέραι πραττοµένων εὐκρασίαν ἐργαζόµεθα τῷ σώµατι, κἀκ ταύτης εἰς ἀρετὴν τῇ ψυχῇ συντελέσοµεν, ὡς οἱ περὶ Πυθαγόραν τε καὶ Πλάτωνα καί τινες ἄλλοι τῶν παλαιῶν ἱστοροῦνται πράξαντες.

We bring about good mixtures in the body through what we eat and drink, and also through our daily practices, and from this good mixture will achieve virtue for the soul—as the associates of Pythagoras and Plato are reported to have done, as well as certain others of the ancients.

Thus, at the beginning of the treatise, Galen attempts to stress the philosophical and ethical importance of what is to follow: when the soul is adequately understood in its dependence upon bodily mixture, it can be improved through adaptation of the mixture. Here we see that the theoretical point of what the substance of the soul is, a question Galen often shied away from answering, has crucial practical consequences that do concern him on a habitual basis.

In what follows, Galen takes up that theoretical question itself. First, he stresses what he designates as ‘the starting point of the entire argument’: the observable differences in actions and affections of small children. What does this mean and why is it so important to Galen’s argument? He argues that these differences imply a difference in the capacities of the souls of these small children and that these differences in capacities imply a difference in the nature or substance of their souls (Galen states that it is evident that the words οὐσία and φύσις mean the same ‘in these kinds of discussions’). For, were the substances of their souls the same, their affections and actions would be the same too. From this we can infer that, whatever the substance of soul will turn out to be in the subsequent discussion, it will have to account for these differences in small children, since that forms, as Galen says, the empirical basis of the entire argument.

Next he attempts to clarify his notion of the terms ‘capacity’ (δύναµις), ‘activity’ (ἐνέργεια) and ‘substance’ (οὐσία) and their interrelation, which has often been misunderstood by ‘many of the philosophers’ (and we shall see later that this is exactly the point where Galen disagrees with Andronicus). The misunderstanding revolves around their notion of ‘capacity’. According to Galen, they conceive of a capacity as being some kind of ‘thing’ that inhabits the substances (τινος πράγµατος ἐνοικοῦντος ταῖς οὐσίαις).5 Instead, Galen explains, a capacity is nothing but a name given in relation to a certain activity. The agent of those activities, the cause, is the substance itself, as his example of aloe makes clear; and in retrospect the substance could thus be said to ‘have’ the capacity for doing what it does. But this does not mean, then, that there is something else required besides the substance itself to give a causal explanation of what takes place (QAM 34.1-10 Müller = iv. 769-70 Kühn):6

καὶ διὰ τοῦτο τοσαύτας δυνάµεις ἔχειν τὴν οὐσίαν φαµέν, ὅσας ἐνεργείας, οἷον τὴν ἀλόην καθαρτικήν τε δύναµιν ἔχειν καὶ τονωτικὴν στοµάχου καὶ τραυµάτων ἐναίµων κολλητικὴν <καὶ> ἰσοπέδων ἑλκῶν ἐπουλωτικὴν <καὶ> ὑγρότητος βλεφάρων ξηραντικήν, οὐ δήπου τῶν εἰρηµένων ἔργων ἕκαστον ἄλλου τινὸς ποιοῦντος παρ’αὐτὴν τὴν ἀλόην. αὕτη γάρ ἐστιν ἡ ταῦτα δρῶσα, καὶ διὰ τὸ δύνασθαι ποιεῖν αὐτὰ τοσαύτας ἐλέχθη δυνάµεις ἔχειν, ὅσα τὰ ἔργα.

And therefore we say that the substance has as many capacities as activities; for example that aloe has a capacity for cleansing and toning the mouth of the stomach, of agglutinating bleeding wounds, of cicatrizing grazes, and of drying the wetness of the eyelids—without there being some other thing that performs each of these actions apart from the aloe itself. For it is the aloe that does these things; and it is because it can do these things that it is said of it that it has these ‘capacities’, as many as the actions.

As Jim Hankinson has put it, the notion of capacity for Galen is a kind of ‘place-holder for a proper, full-blooded causal explanation, a useful form of words to be employed when such an explanation is not yet available, but by no means a substitute for it’.7 Building on the example of the aloe, Galen states that we could say the same thing about the rational soul ‘that is seated in the brain’. That is to say, there is a substance that is doing things such as perceiving and understanding, which we do not know yet but which we have to infer on the basis of the activities that are manifest, and therefore we say that this substance has the capacity for doing these things.

I have put some emphasis on this point, because once we recognize that in Galen’s view it is the substance that is primarily active and that does things, and that we attribute ‘capacities’ to this substance on the basis of its activity, it becomes evident that proving that the substance of the soul is a bodily mixture is more than conducive to proving the thesis that the capacities of the soul are dependent on the mixture of the body. That is to say: Galen establishes here that capacities are per se dependent upon substance since they are what we predicate of substance on the basis of its activities as long as we do not know the actual substance itself, implying that if we do get to know the substance and show the substance of the soul to be a bodily mixture, that is the best proof we can get that the capacities of soul are dependent upon bodily mixture. Thus, this is how the two theses are related: proof for the stronger thesis that states that the substance of the soul is a bodily mixture is the most reliable proof for the weaker thesis that the capacities of soul follow or are dependent upon the mixture of the body.

Next is the introduction of the familiar tripartition and trilocation of soul and the status aparte of its rational part. Galen first remarks that he cannot decide on the question of the immortality of the rational soul, so that he will postpone the discussion of this part and first discuss the souls located in heart and liver, which he does through an exchange with Aristotelian philosophy.

3 The Souls Seated in Heart and Liver

Now, Galen states that each of these organs has its own specific substance (ἴδια οὐσία) and that it has been previously shown by him that the common substance (κοινὴ οὐσία) of all bodies consists of two principles, namely matter and form, matter being without quality and form being a mixture of the four qualities hotness, coldness, dryness and wetness. This is obviously Peripatetic to some extent at least, but that does not mean it is not also Galenic. That is to say, Galen clearly presents this as his own position, as we can corroborate throughout the rest of his work.8 Notice also that now we have made a few leaps from the original question about the substance (or nature) of soul: in introducing the tripartition and trilocation, the discussion has shifted to the substances of the organs, which are then furthermore included in a doctrine on the hylomorphic substance of all bodies. As we shall see, Galen simply assumes the Aristotelian definition of soul as form of the body. The simplest bodies, that are often called ‘perceptible bodies’ or also ‘perceptible elements’ by Galen, are the homoeomerous bodies, which we cannot analyze further except conceptually in terms of their form (mixture of four elemental qualities) and matter (without qualities). In this particular passage, Galen gives the examples of bronze, iron and gold, but also of flesh, sinew, gristle and fat. More complex bodies, among which are the organs, are called anhomoeomerous and are constructed out of a number of homoeomerous bodies.9 So now the question becomes: given that soul is located in these three different organs that are made out of homoeomerous bodies that consist of form and matter, what should be identified as the cause of its respective activities? For, given the assumption that soul is form of the body, there are now two options open for Galen, corresponding to the two respective levels of composition of the organ in which the soul resides: is the cause of our activities to be found in the homoeomerous bodies that constitute the organ, or is it rather to be found in the organ as such? Here Galen’s answer is clear and this is a point where his view seems to depart from most of the Peripatetic tradition (though maybe not all) and certainly from Aristotle (QAM 37.5-15 Müller = iv. 773-4 Kühn):

ὥσθ’ ὅταν αὐτὸς οὗτος ᾿Αριστοτέλης εἶδος εἶναι τοῦ σώµατος εἴπῃ τὴν ψυχήν, ἐρωτητέον αὐτὸν ἢ τούς γ’ ἀπ’ αὐτοῦ πότερον τὴν µορφὴν εἶδος εἰρῆσθαι πρὸς αὐτοῦ νοήσωµεν, ὥσπερ ἐν τοῖς ὀργανικοῖς σώµασιν, ἢ τὴν ἑτέραν ἀρχὴν τῶν φυσικῶν σωµάτων, σῶµα δηµιουργοῦσαν ὅπερ ὁµοιοµερές τ’ ἐστὶ καὶ ἁπλοῦν ὡς πρὸς αἴσθησιν, οὐκ ἔχον ὀργανικὴν σύνθεσιν. ἀποκρινοῦνται γὰρ ἐξ ἀνάγκης τὴν ἑτέραν ἀρχὴν τῶν φυσικῶν σωµάτων, εἴ γε δὴ τούτων εἰσὶ πρώτως ἐνέργειαι (δέδεικται γὰρ τοῦθ’ ἡµῖν ἑτέρωθι καὶ νῦν, ἂν δεήσῃ, πάλιν εἰρήσεται).

Therefore when this Aristotle himself says that the soul is form of the body, one must ask him, or his followers, whether we should understand form here to have been used by him in the sense of shape, as in the organic bodies, or in the sense of the other principle of natural bodies, that which crafts a body that is homoeomerous and simple in terms of perception, not having organic composition. For they have to answer, necessarily, that it is the other principle of the natural bodies—since, indeed, to these the activities primarily belong (this has been shown by us elsewhere, and will be stated again now, if you require).

Assuming these two different principles, operating at different levels of our bodily constitution, Galen identifies the principle that crafts homoeomerous bodies as the proper location of the substance of soul, since the activities belong there primarily. This choice is also in line with Galen’s general assumptions about what constitutes the nature or substance of a being, as we find throughout his work, for example in the opening passage of De Elementis ex Hippocrate, where he states that ‘if we are to obtain precise knowledge of the nature of man or any other being’ we need to determine which parts of it are first and simplest and cannot be further divided.10 Likewise, in In Hippocratis De Natura Hominis, we find Galen repeatedly citing a passage from Plato’s Phaedrus, in which he sees the same methodological approach (Nat. Hom. 5. 1-6 Mewaldt = xv. 5 Kühn, tr. modified from Hankinson, forthcoming):

πρῶτον µὲν εἰ ἁπλοῦν ἢ πολυειδές ἐστιν οὗ περὶ βουλησόµεθα εἶναι αὐτοί τε τεχνικοὶ καὶ ἄλλους δυνατοὶ ποιεῖν, ἔπειτα δὲ, ἂν µὲν ἁπλοῦν ᾖ, σκοπεῖν τὴν δύναµιν αὐτοῦ, τίνα πρὸς τί πέφυκεν εἰς τὸ δρᾶν ἔχον ἢ τίνα εἰς τὸ παθεῖν ὑπό του, ἐὰν δὲ πλείω εἴδη ἔχῃ, ταῦτα ἀριθµησάµενον, ὅπερ ἐφ’ ἑνὸς, τοῦτο ἰδεῖν ἐφ’ ἑκάστου, τὸ τί ποιεῖν αὐτὸ πέφυκεν ἢ τὸ τί παθεῖν ὑπό του.

Concerning anything in which we both want to be technically proficient ourselves and to be able to make others so too, we must first determine whether it is simple or complex, and then, if it turns out to be simple, to examine what power it has by nature for acting, and in respect of what, and what <power> it has for being affected by something; while if it has many forms, we must enumerate them, and then do for each of them what we did in the case of the single one, namely what it by nature does to what, and how it is acted upon and by what.

Galen obviously likes this passage a great deal, for several reasons. First of all, in the immediately preceding context, Hippocrates is credited with having described this as the proper method for investigating nature, and it is implied that the inquiry into soul needs to build on this. In De Methodo Medendi 1.2, Galen summarizes this point as follows: ‘Plato thinks it proper to use in the investigation of the soul the same method as that employed by Hippocrates in the case of the body’ (x. 13-4 Kühn, tr. modified from Hankinson 1991). Again, towards the end of the first book of Nat. Hom., he returns to the quotation from the Phaedrus and says that we can now conclude that Hippocrates did follow this method and that Plato agreed that one must apply this method also for inquiring into soul.11 Here, we must remember that Galen classified QAM, where he discusses the question of the nature or substance of the soul, as a work ‘on Platonic philosophy’. That is to say, it is not unreasonable to think that he is applying this very same method to the nature of the soul, departing from the notion that the soul is form of the body and concluding that soul must then be a mixture of the most elemental qualities, because these are the primary powers of the smallest constituent parts of the organs liver, heart and brain.

Now, if we return to QAM, this is in fact what Galen does next (QAM 37.16-21 Müller = iv. 774 Kühn):12

καὶ µὴν εἴπερ ἐξ ὕλης τε καὶ εἴδους ἅπαντα συνέστηκε τὰ τοιαῦτα σώµατα, δοκεῖ δ’ αὐτῷ τῷ ᾿Αριστοτέλει τῶν τεττάρων ποιοτήτων ἐγγιγνοµένων τῇ ὕλῇ τὸ φυσικὸν γίγνεσθαι σῶµα, τὴν ἐκ τούτων κρᾶσιν ἀναγκαῖον αὐτοῦ τίθεσθαι τὸ εἶδος, ὥστε πως καὶ ἡ τῆς ψυχῆς οὐσία κρᾶσίς τις ἔσται τῶν τεττάρων.

And surely if all such bodies are composed of matter and form, but according to Aristotle himself the natural body comes to be because the four qualities come to be in the matter, it is necessary to posit the mixture of these as the form of it, so that the substance of the soul too will somehow be some mixture of the four.

Now, it is important to note that this view, that the four elemental qualities constitute the substance of a thing and are the primary cause of its activities, is not something we only find in QAM, which might be considered philosophically more speculative, but rather something we find throughout Galen’s work. Just to give an example (Hipp. Elem. 132.9-13 De Lacy = i. 485 Kühn, tr. DeLacy):

εἴπερ οὖν αὗται µὲν ἴδιαί τινων ὑπάρχουσι ζῴων, αἱ δὲ τὴν ὅλην οὐσίαν ἀλλοιοῦσαί τε καὶ µεταβάλλουσαι πρῶταί τέ εἰσι τῇ φύσει καὶ κοιναὶ πάντων τῶν ὄντων καὶ τῶν στοιχείων δηµιουργοί, δῆλον, ὡς ὑγρότης καὶ ξηρότης καὶ θερµότης καὶ ψυχρότης ἑκάστου τῶν ὄντων συνιστῶσι τὴν οὐσίαν.

If then these (qualities) are peculiar to some animals, but those that alter and transform the whole substance are primary in nature and common to all existing things and are artisans of the elements, it is clear that wet, dry, hot and cold form the substance of each thing that exists.

The elementary qualities make up the substance of each individual thing.13 Galen referred to this substance in the passage from QAM we cited earlier, saying that each of the organs in which the soul resides has its own particular substance (ἔχοντος δ’ ἰδίαν οὐσίαν ἑκατέρου τῶν σπλάγχνων). Now we can perhaps start to think of a different way in which the soul is seated ‘in’ the organs. That is to say, in the sense that there are substances in the organ, that are cause of the activities which we qualify as psychic.

From these observations we can gather that the preliminary conclusion developed in QAM in interaction with Peripatetic philosophy—that the substance of soul must be a specific mixture of elemental qualities in the organs in which soul resides—is consistent with (I would almost say ‘follows from’) (1) Galen’s general methodology for establishing the nature or substance of things and (2) his view on the primary role of the elementary qualities with regard to determining substance and activity.

4 The Rational Part of the Soul

We return to QAM. After the conclusion that the substance of the souls seated in heart and liver must be mixtures of the elemental qualities, Galen is now ready to move on to the previously postponed subject of the rational part of the soul (QAM 37.1-38,8 Müller = iv. 774-5 Kühn):14

εἰ µὲν οὖν τὸ λογιζόµενον εἶδος τῆς ψυχῆς ἐστι θνητόν, ἔσται καὶ αὐτὸ κρᾶσις τις ἐγκεφάλου· καὶ πάνθ’ οὕτω τὰ τῆς ψυχῆς εἴδη τε καὶ µέρη τὰς δυνάµεις ἑποµένας ἕξει τῇ κράσει, τουτέστιν τῇ τῆς ψυχῆς οὐσίᾳ· εἰ δ’ ἀθάνατον ἔσται, ὡς Πλάτων βούλεται, διὰ τί χωρίζεται ψυχθέντος σφοδρῶς ἢ ὑπερθερµανθέντος ἢ ὑπερξερανθέντος ἢ ὑπερυγρανθέντος τοῦ ἐγκεφάλου, καλῶς ἂν ἐπεποιήκει γράψας αὐτὸς ὥσπερ καὶ τἆλλα τὰ κατὰ ταύτην ἔγραψεν.

Thus if the reasoning form of the soul is mortal, it too will be a particular mixture, [namely] of the brain; and then all the forms and parts of the soul will have their capacities dependent on the mixture—that is, on the substance of the soul; but if it turns out to be immortal, as Plato would have it, he would have done well, himself, to write an explanation as to why it is separated when the brain is excessively cooled, heated, dried or moistened, as he wrote about the other matters concerning it.

Galen adds that we unfortunately cannot question Plato himself about this issue, given that he is no longer around (I think one can gather Galen’s position from this joking remark alone). At this point, the interaction with Aristotelian philosophy is concluded, but what remains is the conclusion that the substances of the two souls that are certainly considered mortal by Galen, are mixtures. Now, for the first time, it is suggested that the same conclusion might be applied to the rational part of the soul as well. It is important to note that Galen presents the discussion for the rational part in the form of a disjunction: if it is mortal, it is a mixture as well; if it is immortal, we would need a different explanation, since for Galen that implies that it ‘has a nature of its own’, i.e. some nature that is separable from the body.15 Obviously, the rational soul has to be either mortal or immortal: there is no further option. In what immediately follows, Galen proceeds to argue against one side of the disjunction, namely that the rational soul is immortal or that it has a separate existence of some kind, mostly by showing how the observational evidence speaks against it.16 Hence, given the overall structure of his discussion, these arguments can be taken as supporting the other option, viz. that the rational soul is mortal, from which it follows, according to Galen, that the rational soul is a mixture as well, that is, as the other two souls have been shown to be.17 Also, we can clearly see the relation between the two theses of QAM in this passage: if it is shown that the rational form is mortal and thus a mixture, it has been proven that the capacities of all three souls are dependent upon a bodily mixture.

This view, that all three parts of soul are mixtures, presented here in hypothetical form, is the same as the view that Galen approvingly ascribes to Andronicus a bit further in the text, right after he has argued against the immortality and incorporeal existence of (the rational part of) the soul. The structure of the text, surprisingly ignored in most scholarship, is telling in that regard.

Let us now first have a look at the way Galen presents Andronicus’ position, after the arguments against the immortality of the soul (QAM 44.12-45.3 Müller = iv. 782-3 Kühn):18

Ἀνδρόνικον δὲ τὸν Περιπατητικόν, ὅτι µὲν ὅλως ἐτόλµησεν ἀποφήνασθαι τὴν οὐσίαν τῆς ψυχῆς ὡς ἐλεύθερος ἀνὴρ ἄνευ τοῦ περιπλέκειν ἀσαφῶς, ἐπαινῶ τε πάνυ καὶ ἀποδέχοµαι τὴν προαίρεσιν τἀνδρός· εὑρίσκω γὰρ αὐτὸν καὶ κατ’ ἄλλα πολλὰ τοιοῦτον· ὅτι δέ τοι κρᾶσιν εἶναί φησιν ἢ δύναµιν ἑποµένην τῇ κράσει, µέµφοµαι τῇ προσθέσει τῆς δυνάµεως. εἰ γὰρ ἡ ψυχὴ πολλὰς ἔχει δυνάµεις οὐσία τις οὖσα καὶ τοῦτ’ ὀρθῶς ᾿Αριστοτέλει λέλεκται … ὑπάρχειν οὐκ ἐγχωρεῖ ἄλλο τι παρὰ τὴν κρᾶσιν, ὡς ὀλίγον ἔµπροσθεν ἐδείκνυτο.

And as for Andronicus the Peripatetic, because he dared to speak out on the substance of the soul as a whole, in the manner of a free man without beating around the bush, I praise him highly and I accept the position of the man (and I find him similar in many other areas, too). But surely when he says that it is a mixture or a capacity dependent on the mixture, I disapprove of the addition of capacity. For if the soul has many capacities, while itself being some kind of substance, and this has been said correctly by Aristotle … it is not possible for it to be anything else but the mixture, as has been demonstrated a little before.

First of all, it is notable that Galen here emphasizes Andronicus’ audacity. Apparently, he considers it daring to argue freely for the substance of the soul being a mixture. Why would that be? In fact, this is a recurring motif in Galen. A few pages earlier, when arguing against the possibility that the soul is immortal, Galen said that he ‘dares’ to state—against Plato—that not every kind of body is suitable to receive the rational soul (which implies that the rational soul is dependent upon a specific bodily constitution, which implies that it does not have a nature separate from the body, which implies that it is mortal) (QAM 38.16-23 Müller = iv. 775-6 Kühn):

τολµῶ λέγειν αὐτός, ὡς οὐ πᾶν εἶδος σώµατος ἐπιτήδειόν ἐστιν ὑποδέξασθαι τὴν λογιστικὴν ψυχήν. ἀκόλουθον γὰρ ὁρῶ τοῦτο τῷ περὶ ψυχῆς δόγµατι τοῦ Πλάτωνος, ἀπόδειξιν δ’ οὐδεµίαν ἔχω λέγειν αὐτοῦ διὰ τὸ µὴ γιγνώσκειν µε τὴν οὐσίαν τῆς ψυχῆς ὁποία τις ἐστιν, ἐκ τοῦ γένους τῶν ἀσωµάτων ὑποθεµένων ἡµῶν ὑπάρχειν αὐτήν.

I dare to state myself, that not every kind of body is suitable to receive the rational soul. For I see this as consequent upon Plato’s doctrine of the soul, but I am not able to state any demonstration for it, because I wouldn’t know what kind of thing the substance of the soul is, if we take as our assumption that it belongs to the class of non-bodily things.

Furthermore, there is a remarkable passage in his Prognosis by the Pulse (Praes. Puls.), as Matyáš Havrda has noted,19 where Galen says that he previously did not dare to assert anything about the substance of the capacity of pulse, but that now he does (2.8, ix. 305.16-306.4 Kühn, tr. after Havrda 2017, 77):

οὐδὲ γὰρ οὐδὲ τοῦτο τὸ δόγµα, πρὶν ἐν ἅπασι τοῖς κατὰ µέρος ὁµολογουµένοις ἐξευρεῖν, ἐτολµήσαµεν ἀποφήνασθαι. νῦν δ’ ἐπειδὴ πεπείσµεθά τε τὴν οὐσίαν τῶν δυνάµεων οὐδὲν ἄλλο παρὰ τὴν ποιὰν εἶναι κρᾶσιν, ἅπαντά τε τὰ κατὰ τὰς διαγνώσεις τε καὶ προρρήσεις καὶ θεραπείας ἐπὶ τούτῳ τῷ δόγµατι συµφωνοῦνθ’ εὑρίσκοµεν, εὐλόγως, οἶµαι, καὶ τοὺς ἑποµένους ταῖς ἀνωµάλοις δυσκρασίαις τῆς καρδίας σφυγµοὺς ἐνταῦθα διήλθοµεν.

This is because I did not dare to assert this belief, before finding out if all particular [observations] are in agreement with it. But now, since we have already been convinced that the substance of capacities is nothing but a particular mixture and, since we have found that all [observations] regarding diagnosis, prognosis and therapy are in agreement with this view, it was reasonable, I suppose, that we would also give an account on this occasion of pulses that follow the anomalous imbalances of mixture in the heart.

Interestingly, Galen here states the reason for his previous carefulness: first it had to be established that all observations are in agreement with it. Here we may recall that in QAM Galen placed great emphasis on the observable differences between small children as the starting point of his argument and we may also think of the observational evidence that he presents as being at odds with the Platonic notion of an immortal soul. In yet another work, De Symptomatum Causis, Galen states that he might have the audacity to make a statement with regard to the substance of the soul elsewhere.20 Now in QAM, we find Galen applauding Andronicus for making such a statement and expressing his approval of it, except for the fact that Andronicus said—according to Galen—that the substance of the soul could also be a capacity dependent on the mixture. This is clearly at odds with Galen’s previous definitions of capacity and substance, as we have seen. Therefore, he clarifies that a substance could be said to have capacities, but not to be itself a capacity, and that therefore the substance of the soul can only be a mixture, as he now takes himself to have demonstrated already.21

At this point, however, we are not even halfway through QAM: Galen still proceeds to give many examples, basing himself on Aristotle, Hippocrates and Plato, that aim to show that the bodily mixture in one way or another determines the state or activity of soul. That is to say, he proceeds to argue for the weaker thesis of QAM described in its title. There is a clear demarcation in the text, where Galen moves from arguing for the stronger thesis to the weaker one, in which he says the following (QAM 48.3-8 Müller = iv. 787 Kühn):22

εἰ µὲν γὰρ εἶδός ἐστιν ὁµοιοµεροῦς σώµατος ἡ ψυχή, τὴν ἀπόδειξιν ἐξ αὐτῆς τῆς οὐσίας ἕξοµεν ἐπιστηµονικωτάτην· εἰ δ’ ὑποθοίµεθα ταύτην ἀθάνατον εἶναι φύσιν ἰδίαν ἔχουσαν, ὡς ὁ Πλάτων ἔλεγεν, ἀλλὰ τὸ γε δεσπόζεσθαι καὶ δουλεύειν τῷ σώµατι καὶ κατ’ αὐτὸν ἐκεῖνον ὁµολογεῖται.

For if, on the one hand, the soul is a form of a homoeomerous body, we shall have the demonstration based on its very substance, which is the most scientific demonstration possible. If, on the other hand, we would take it to be something immortal, having a nature of itself, as Plato said, even then he himself agrees that it is dominated by and enslaved to the body.

The ‘demonstration’ here refers to the demonstration of the central thesis of QAM, as the preceding sentences make clear. The most scientific demonstration of this thesis is that proceeding from the substance of the soul, namely the demonstration that shows that the substance of the soul must be the form of a homoeomerous body, that is to say, the mixture of elemental qualities. Again, such a demonstration would logically imply that the capacities of the soul are dependent on the mixtures, since capacities are dependent on the substance of which they are said to be capacities. But, states Galen, even if we would take the soul to be something immortal, which would mean that the central thesis of QAM would not be directly proven from the substance of the soul itself, then we could still prove the central thesis, even by means of what Plato himself has said. Hence, in the remaining part of QAM Galen proceeds to take up the other side of the disjunction he set out when starting the section about the rational soul, although it has already been repudiated, and shows how even if the immortality and separate nature of soul would be accepted, QAM’s weaker thesis still remains true.

That, however, is not what concerns us here. What remains now, is to refine our analysis of the argument for the strong thesis in QAM by comparison with Prop. Plac., one of Galen’s latest works in which he again expresses his ‘agnosticism’ with regard to the substance of the soul.

5 Prop. Plac. and the Distinction between Knowledge and What is Plausible

In Prop. Plac., Galen explicitly claims several times that he does not know what the substance of the soul is.23 Unfortunately, he does not refer to QAM at all, which is remarkable in itself. In this regard, it is important to note the explicit strategic aim of Prop. Plac: Galen, finding himself in a similar situation as the poet Parthenios, as he states, is defending himself against wrong interpretations of his works. He presents this predicament as the very reason for writing the work.

More specifically, Galen remarks that people have often misunderstood the status of some of the things he wrote. Thus, there has apparently been a mix-up of things he has claimed to know and things he has merely claimed to find plausible (περὶ ὧν ἀπεφηνάµην ὡς βεβαίως ἐπιστάµενος ἢ κατὰ µόνον τὸ πιθανός); presumably, considering the apologetic and careful tone of the whole text, others have taken some views that Galen has presented as plausible as if they were presented by him as having the status of scientific knowledge.

Now, if we look at what he has to say on the substance of the soul in particular, we notice that, despite the fact that QAM is not explicitly referred to, the views that are elaborated there certainly do surface here as well. In Prop. Plac. 7.2, we find something quite reminiscent of what we read in QAM, interestingly right after Galen again remarked that he does not know what the substance of the soul is (p. 86 Garofalo and Lami = 178.29 ff. Boudon-Pietrobelli):

εἶναί τε τούτων γένε(σιν ἐκ) τῆς ποιᾶς κράσεως τῶν τεσσάρων στοιχείων, καὶ εἴπερ (ἡ ψυχὴ ἅµα τῷ) διαπλαττ(όµενῳ) σώµατι, τὴν γένεσιν ἔχει, (διὰ δὴ τ(ὴν) τῶν τεσσάρων στοιχείων κρᾶσιν αὐτὴν γίνεσθαι, οὐκ ἄλλ(ης) (µὲν) οὔσης τῇ (ψυ)χῇ γενέσεως, ἄλλης δὲ τῷ αἰσθητικῷ σώµατι· µ(ὴ γὰρ) εἶναί που ψυχῆς οὐσίαν καθ’ ἑαυτήν, (ἀλλ’ οἷ)ον εἶδός τι τοῦ σώµατος ὑπάρχειν αὐτήν· ἄκουε δέ µου λέγοντος εἶδος ὡς πρὸς τὴν τῆς ὕλης ἀντίθεσιν, ἣν ἄ(ποιον) εἶναι νοοῦµεν ὅσον τὸ ἐφ’ ἑαυτῇ.

And that the generation of them [the organs of perception] is from the specific mixture of the four elements, and if the soul has its generation together with the formation of the body, then it itself comes to be because of the mixture of the four elements, since there is not one generation of the soul, and another of the sense-perceiving body; and I suppose that there is not a substance of the soul existing by itself, but that it is a kind of form of the body; understand when I say form I mean the opposite of matter, which we understand to be without quality taken in itself.

Here, pretty much immediately after saying that he does not know the substance of the soul, Galen proceeds to suggest that the soul comes to be from the mixture of elements, that the soul does not have a generation separate from that of the body, that there is no separate substance of the soul (remember here the disjunction from QAM) and that the substance of the soul is rather a kind of form of the body. These are exactly the same views as those he expounds in QAM. How is it possible, then, that Galen can say all this about the substance of the soul—that it is the form of the body, and that form is to be understood as a mixture of the four elemental qualities, since it is the form of the most basic matter—while at the same time proclaiming that he does not know what the substance of the soul is? The answer to this question is really quite simple, I think, and lies in the difference he made at the outset of Prop. Plac., between what he thinks he knows and what he thinks is plausible. The εἶναι cited at the start of this passage is dependent on a previous εὔλογον νοµίζω, ‘I consider it reasonable’, and as we have seen Galen also adds an extra που, ‘I think / suppose’, when he gives his take on the actual substance of the soul. By contrast, at the start of Prop. Plac. 7, and again after the passage cited above, where he denied knowledge of the substance of the soul, he expresses himself in a much stronger vocabulary, using forms of ἀγνοεῖν and (οὐ) γιγνώσκω. Hence, in this late work that seems ‘as much an apology as a career conspectus’, as Aileen Das has aptly put it,24 Galen states that although he does not know what the substance of the soul is, he does consider the notion that it is a mixture of elemental qualities reasonable or likely. It seems as if he regards this view as belonging to the class of plausible ones, having some persuasiveness about it. I think that, in this case at least, that means that he distinguishes it not only from views that have scientific status, but also from views that qualify neither as knowledge nor even as plausible. In this regard, it is important to realize that Galen does not only contrast what is plausible (πιθανός) with what is certainly true, but also with what is completely unlikely (ἀτοπία).25

Further on in Prop. Plac., we find another passage reminiscent of QAM, particularly of the passage on the relation between substance, activities and capacities (14.1, p. 128 Garofalo and Lami = 187.14-22 Boudon-Pietrobelli):

Περὶ <δὲ> τῆς οὐσίας τῶν ψυχικῶν δυνάµεων, ὅτι ψυχὴ ἔχοµεν, ἐπίσταµαι ὥσπερ πάντες ἄνθρωποι, θεώµενοι µὲν ἐναργῶς τὰ διὰ τοῦ σώµατος ἐνεργούµενα, βαδιζόντων καὶ τρεχόντων <καὶ> ἔσθ’ ὅτε καὶ παλαιόντων αἰσθανοµένων τε πολυειδῶς· ἐννοοῦντες δὲ τῶν ἔργων τούτων αἰτίας τινὰς ὑπάρχειν ἔκ τινος ἀξιώµατος φυσικοῦ πᾶσιν ἡµῖν πιστοῦ, καθ’ ὅ µηδὲν ἀναιτίως γίνεσθαι νοοῦµεν, ἀλλὰ διὰ τὸ µὴ γινώσκειν, ἥτις ἐστὶν ἡ αἰτία τῶν ἔργων τούτων, ὅνοµα θέµενοι ἀπὸ τοῦ δύνασθαι ποιεῖν ἃ ποιεῖ, δύναµιν [εἶναι] τῶν γινοµένων ἑκάστου ποιητικήν.

With regard to the substance of the psychic capacities, that we have a soul, I know as all men do, because we clearly see the activities performed by the body, walking and running and sometimes also wrestling, and sense-perception of many kinds, and because we understand that there are certain causes of these actions, on the basis of a natural axioma trusted by all of us, according to which we consider nothing to happen without cause; but because we do not know what the cause of these actions is, we postulate a name based on the [subject] being able to do the things that it does, a capacity as the efficient cause of each of the things that happen.

As in the introductory passage of QAM, δύναµις is explained as a mere appellation (ὄνοµα), because the true efficient cause of the activities, the substance (οὐσία), is unknown. The fact that the activities are there prove that soul exists as their cause (just as, for Galen, the existence of well-designed creatures proves that an intelligent creator exists), but because we do not know what soul itself is, we name the causes of the activities in terms of capacities, while it is really the substance that is the cause.26 As in QAM, where it was aloe, Galen gives examples of the capacities of substances used for medical purposes, scammony and medlar in this case.

Now Galen proceeds to enumerate two basic positions with regard to what the soul is: there are those that state that incorporeal capacities ‘inhabit’ (ἐνοικεῖν) the perceptible substances (ταῖς αἰσθηταῖς οὐσίαις, this term refers to the homoeomerous bodies), and those of the opinion that the substances themselves act according to their own particular nature (οἱ δὲ αὐτὰς ἐνεργεῖν τὰς οὐσίας κατ’ ἰδίαν ἑκάστης φύσιν). The latter view is in accordance with the notion that the substances themselves are the true efficient causes of activities, presented just a little earlier and argued for in QAM (Prop. Plac. 14.3, p. 132 Garofalo and Lami = 188.1-6 Boudon-Pietrobelli):

καθάπερ ἄλλοι µηδ’ εἶναί τινα ὕπαρξιν αὐτῆς ἰδίαν, ἀλλὰ τὴν ἰδιότητα τῆς τοῦ σώµατος οὐσίας, ὧν ποιεῖν πέφυκε, τούτων ἔχειν λέγεσθαι δυνάµεις, οὐκ οὐσ<ι>ῶν τινων ἐκείνων ἰδίαν φύσιν ἐχουσῶν, ἀλλὰ τῆς ἐνεργούσης οὐσίας καὶ αὐτῆς πρὸς τὰ γινόµενα δι’ αὐτῆς τε καὶ ὑπ’ αὐτῆς δυνάµεις ἔχειν λεγοµένης, ὧν πέφυκε δρᾶν.27

And according to others [the soul] does not have some existence of its own, but the particular nature of the substance of the body is said to have capacities of those things which it does naturally, since it is not the case that the capacities possess the particular nature of certain substances, but rather the substance that is acting is said to have capacities for the things which it does naturally with regard to the things that happen through it and because of it.

Again, we find the view that it is the bodily substance, and its peculiar nature, that is the cause of the activity on the basis of which we infer the existence of soul. In this view, it is really the particular constitution of the substance of the body itself that is cause, rather than any capacity that follows from it—remember Galen’s objection to the position of Andronicus in QAM.

Galen, interestingly, proceeds to state after his enumeration of the various possible positions that he has positioned himself somewhere midway in this discussion: on some other subjects he has spoken clearly, some of which he has known the truth of, and some of which he did not know anything at all, but in the discussion at hand he goes as far as stating what is plausible (πιθανοῦ), although he thinks that it would be better to have a sure knowledge on this subject. Therefore, it seems to me that we should understand the ‘middle position’ that Galen says he has been taking, to refer to the epistemological status of his position in this debate, rather than to a position in between the actual views of the soul being incorporeal or not having a separate substance. As to those views, it is clear enough, I think, from the nearly complete correspondence between what is said in QAM and Prop. Plac. on the subject, where Galen’s sympathies lie—namely with the view that the soul (i.e. the cause of activity) does not have a separate existence and is rather a bodily mixture—but he simply qualifies this subject as (currently) outside the domain of things he knows for certain, and considers his views on the matter to be plausible rather than having the status of certain knowledge.28 That does not mean, however, that he does not find his position more plausible than that of someone who holds that the soul is a separate incorporeal substance inhabiting the body and it certainly does not mean that he has no view on the subject altogether. It means that Galen has an opinion on what the substance of soul is, that builds on his previous work as well as on what he considers to be the observational evidence, but that cannot (yet) be proven in a conclusive scientific manner. With regard to QAM, I think that, more than anything else, it is Galen’s exploration of what he considers to be a plausible view with regard to the tricky subject of the substance of the soul.29


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Most recently, Peter Singer has ingeniously argued that Galen is not truly committed to the positions presented in QAM, but rather presents the consequences of what he sees as an Aristotelian position, so that any ‘more extreme statement’ or ‘apparent inconsistency’, can be resolved by recognizing the hypothetical nature of the argument and conjecturing a ‘conditional clause with the fundamental sense: “if Aristotle is right”’ (Singer 2013, 335-73). This interpretation was previously advocated by the Spanish scholar Garcia-Ballester in an attempt to account for QAM’s ‘vagueness’. Garcia-Ballester also suggested that ‘the involvement of socio-professional interests in motivating the formulation of such an extremely radical naturalism by Galen’ (1988, 117-52, esp. 125-30). The latter approach has been worked out in more detail by Lloyd and Donini. Donini has proposed that as long as we interpret QAM as a ‘more or less propagandizing manifesto devoted principally to promoting the image and the office of the doctor … the threatened contradictions with respect to Galen’s other works disappear’ (2008, 200). According to Donini, ‘Galen was fully conscious of the fact that in this treatise he was speaking at a different, indeed considerably lower, level than that of PHP’ (2008, 201). Lloyd (1988, 42) states the same idea in a somewhat more careful manner: ‘this would mean that his contributions to the debates on the relations between the soul and body, and to moral philosophical issues, are in places subordinated to a strategic concern with the prestige and power of the doctor’. I think that it is true that Aristotelian philosophy and terminology play an important role in QAM, but I also think that a close reading of the text—as we shall undertake below—simply does not allow us to discard the thesis of the soul being a mixture as merely spelling out the supposed consequences of an Aristotelian position. Rather, as we shall see, this thesis can be understood as Aristotelian to the extent to which Galen’s own position could be said to be Aristotelian. Naturally, the fact that Galen is a doctor and fervent advocate of the medical science has a strong and direct influence on his philosophical thinking and writing. However, to explain his supposedly ‘extreme’ or ‘radical’ views on the soul in terms of a kind of power-play between doctor and philosopher, is to radically reduce the richness and originality of the text, as well as Galen’s self-understanding and his constructive relation towards philosophy, as I hope to show.


Vegetti 2000; Tieleman 2003; also more recently Marechal 2019.


Cf. Frede 2003; Chiaradonna 2014; Tieleman 2018.


Translations of QAM are from Singer 2013, sometimes with modification.


QAM 33.17-28 Müller = iv. 769 Kühn.


Cf. Nat. Fac. 1.4, ii. 9-10 Kühn: ‘But, if the cause is relative to something—for it is the cause of what results from it, and of nothing else—it is obvious that the capacity also falls into the category of the relative; and so long as we are ignorant of the substance [τὴν οὐσίαν] of the cause which is active, we call it a capacity [δύναµιν]’ (tr. Brock 1916, slightly modified). Also Prop. Plac. 14, p. 128 Garofalo and Lami; Caus. Puls. ix. 5 Kühn: τίνος γὰρ ἡ δύναµις ἐστι καὶ τὴν νόησιν αὐτῆς ἐν τῷ πρὸς τὶ κεκτήµεθα, καὶ διὰ τοῦτο οὕτως αὐτὴν ὀνοµάζοµεν, ὅταν τὴν οὐσίαν ἀγνοοῦµεν. See also Frede 2003, 94 with reference to Prop. Plac. 14: ‘We know that there is a soul, because the soul makes us do the things we as living beings do, like walk or run. But we do not know what it is, and hence also do not know what it does such that as a result of it we walk and run and do all the other things living beings do. Hence we introduce powers named after the observable effects of its activity, of its exercise of its power, for instance the natural powers’.


Hankinson 2003, 51; see also Hankinson 2006, 242 ff. and 2014, 964 ff.; Tieleman 2003, 144-51; Chiaradonna unpublished.


Hipp. Elem. 114.16 ff. and 126.1 ff. De Lacy; Nat. Hom. 17.28-18.15 Mewaldt (= xv. 30-1 Kühn); Prop. Plac. 7.2, p. 86 Garofalo and Lami (cited below); Hankinson 2008, 210-36 and 2017; Kupreeva 2014, with an interesting comparison to Boethus (ap. Simplicius, In Cat. 78.10-20 Kalbfleisch) that suggests that perhaps there were Peripatetic precedents for Galen’s particular view (see also Chiaradonna unpublished on this). There is of course also a Stoic tradition of dualism in which one of the principles is a prime matter without quality and the other is the active principle (cf. Sedley 2011): there are obviously differences between that account and Galen’s, but there are also resemblances. Interestingly, as Sedley has shown, the Stoics strongly based this dualism on Plato’s Timaeus, which happens to have been one of Galen’s favourite philosophical works as well.


For this distinction, which Galen takes from Aristotle (e.g. PA 2.1, 646a12-24): Nat. Hom. 6, 11 ff. Mewaldt (= xv. 7-8 Kühn); PHP 8.4, 500.3 ff. De Lacy; Part. Hom. Diff., including Strohmaier 1970, 87-94.


Hipp. Elem. 58.2-5 De Lacy: ἀλλὰ τὰ πρῶτά τε καὶ ἁπλούστατα τῇ φύσει καὶ µηκέτ’ εἰς ἄλλα διαλυθῆναι δυνάµενα ζητῶµεν, εἰ µέλλοιµεν ἢ ἀνθρώπου φύσεως ἤ τινος ἄλλου τῶν ὄντων ἐπιστήµην ἀκριβῆ λήψεσθαι.


Nat. Hom. xv. 53.15-54.12 Mewaldt = xv. 102-3 Kühn.


I follow Müller and Bazou and do not take over Singer’s reading αὐτὸν for αὐτοῦ (apparently supported by the Arabic, but not in the Greek MS tradition), which would give ‘it is necessary for him’ (i.e. Aristotle), and eliminate the ‘of it’ (referring to the matter) after ‘form’. Cf. Singer 2013 ad loc. (Singer’s reading supports his interpretation of Galen’s argument being hypothetical, spelling out the consequences of an Aristotelian position.) Singer also remarks in a note to his translation (2013, 381 n. 38) that ‘the adverb [πως] suggests that this is a surprising conclusion which is nonetheless drawn’. He translates πως as ‘it seems as if’ (‘so that it seems as if the substance of the soul, too, will be some mixture of the four …’). In my view, πως can be translated simply as ‘somehow’, referring to the immediately following remark, that this ‘mixture of the four’ can be understood in several ways (εἴτε … εἴτε …), namely as a mixture of qualities (ποιοτήτων) or bodies (σωµάτων). Cf. Moraux’s translation (1984, 780).


See also Hipp. Elem. 138.15-17 De Lacy (= i. 492 Kühn); Nat. Fac. ii. 134 Kühn; Nat. Hom. 17.18 ff. Mewaldt (= xv. 29-30 Kühn), 22.4-8 Mewaldt (38 Kühn), 28.10-14 Mewaldt (51 Kühn).


Here I follow Bazou’s text, except for her addition of αὕτη after διὰ τί χωρίζεται (which I agree with Singer seems unnecessary) and in line 8 reading ἔσται in accordance with the MSS, rather than Bazou’s ἐστιν in accordance with the Arabic (cf. Singer 2013, Textual Notes 4.13-15).


QAM 48.5-6 Müller (= iv. 787 Kühn) but following Singer (2013, Textual Note 4.27) not accepting the emendation ἀσώµατον for ἀθάνατον (Goulston, Müller, Bazou); QAM 46.17-23 Müller (= iv. 785 Kühn).


This might seem surprising, given that Galen considers QAM a work ‘on Platonic philosophy’, as we have mentioned, but it does fit with Galen’s general interpretation of Plato, particularly of the Timaeus, of which he seemed to have advocated a reading in which the opposition between body and (rational) soul is to some extent recast into an opposition of different elemental qualities. Although the immortality or separate existence of the soul may appear as one of the most fundamental Platonic doctrines, Galen has an elaborate interaction with the Timaeus without accepting this doctrine. This comes to the fore in his so-called Compendium of the Timaeus (which is an interpretative work at least as much as it is a mere summary), in the fragments of his Timaeus commentary collected in Daremberg 1848 and later re-published in Schröder and Kahle 1934, a few other scattered places in the Galenic corpus, and finally also in the excerpts collected by Larrain, of which the authenticity is at least doubtful, but which might have been based on Galen’s actual commentary on the Timaeus. This topic cannot be further pursued in the present paper, but will be treated more extensively in my forthcoming dissertation.


Clearly, the rational soul does have an exceptional position in Galen’s discussion, particularly because it has the capacity to transform the bodily mixture to some extent, but there is no space to pursue this further here either. When Neoplatonist authors such as Proclus, John Philoponus and Olympiodorus refer to QAM, however, the main thesis is generally accepted as long as the rational part is exempted: see Proclus, In Remp. i. 222 Kroll; Olympiodorus, Commentary on Plato’s Gorgias 49.6 Westerink (ad 524d5-6); Philoponus, On Aristotle’s On the Soul 50.32 ff. Hayduck (and the notes as loc. in van der Eijk 2006).


I follow Bazou in omitting Müller’s addition κρᾶσιν ἢ δύναµιν εἶναι τοῦ σώµατος after τὴν οὐσίαν τῆς ψυχῆς in his line 14 (see also Singer 2013, n. 62 ad loc.), and following the suggestion to place ὑπάρχειν after the parenthesis, which renders Müller’s conjectural λέγειν (followed by Bazou) unnecessary. Cf. Singer 2013, Textual Note 4.21.


Havrda 2017, 77; cf. also Ut. Resp. iv. 472 Kühn.


Caus. Symp. vii. 191 Kühn: αὐτῆς µὲν γὰρ τῆς ψυχῆς τὴν οὐσίαν ἴσως µὲν καὶ κατ’ ἄλλην τινὰ πραγµατείαν ἀποφήνασθαι τολµηρὸν; cf. also Frede 2003, 79 on UP: ‘There clearly is some suggestion of the inscrutability of nature’s or the Demiurge’s ways, of the impropriety of daring (τολµᾶν, II p. 342,6 and 8) to inquire into things which it is not for human beings to know.’


Interestingly, according to Themistius, Andronicus held that the soul is cause of the mixture, as a tuning that attunes itself. This seems to be at odds with the way Galen presents his view. However, we could perhaps align Galen’s depiction of Andronicus with that found in Themistius, if we take Galen’s distinction between substance and capacity here to refer to a specific kind of mixture and its capacity to be a cause of movement, so that Andronicus’ position would be that soul is the tuning that causes the specific mixture to which the capacity for self-movement belongs, which would then cause confusion over which properly should be called soul: the tuning or the resulting capacity for self-movement. Galen would then disagree with the addition of capacity, because in QAM he rather suggests that the cause of movement is the mixture itself, that is to say, it as a specific bodily mixture. See Themistius’ commentary on De Anima at 32.26-31 Heinze: σχεδὸν οὖν ταὐτὸν ἀπεφαίνοντο τοῖς ἁρµονίαν αὐτὴν τιθεµένοις, πλὴν ὅσῳ σαφέστερον οὗτοι τῇ προσθήκῃ τὸν λόγον ἐποίουν, οὐ πάντα ἀριθµόν, ἀλλὰ τὸν κινοῦντα ἑαυτὸν τὴν ψυχὴν ἀφοριζόµενοι, ὥσπερ ἂν εἰ καὶ ἐκεῖνοι µὴ πᾶσαν ἁρµονίαν, ἀλλὰ τὴν ἁρµόζουσαν ἑαυτήν· αὐτὴ γάρ ἐστιν ἡ ψυχὴ τῆς κράσεως ταύτης αἰτία καὶ τοῦ λόγου καὶ τῆς µίξεως τῶν πρώτων στοιχείων. (I thank Jaap Mansfeld for pointing out this passage.) Cf. Moraux 1973, 45-143, esp. 132-4; Chiaradonna unpublished.


Following Singer, I stay with the MSS tradition here, reading ἀθάνατον and not accepting the emendation ἀσώµατον (Goulston, Müller, Bazou) in 48.7-8 Müler (cf. Singer 2013, Textual Note 4.27)—but for a different reason: Galen here returns to the earlier disjunction between the soul being mortal (and thus a mixture) or immortal. This also means that the difference between ἀθάνατον and ἀσώµατον is not as important as it might seem here, since they necessarily go together for Galen in this argument.


Prop. Plac. 3.1, p. 64 Garofalo and Lami [173.16-18 Boudon-Pietrobelli]; 7.1, p. 86 [179.28-9]; 15.1, pp. 136-8 [188 27-30].


Das 2014, 2.


An example is Hipp. Elem. 86.14 De Lacy (= i. 442 Kühn); but on Galen’s use of πιθανός, see Chiaradonna 2014 and Tieleman 2018.


Cf. Frede 2003, 94 and Tieleman 2003 on Galen’s use of these terms in their relation to previous Platonist tradition.


While it is attractive to speculate on particular people Galen might have had in mind with his ἄλλοι, the immediate context suggests that ἄλλοι includes everyone that does not accept either incorporeal substances or incorporeal capacities that inhabit substances as the cause of activities considered psychic. Those that define the particular nature of the body in terms of mixture of the four elements, in terms of atoms or in fact any other equivalent, are all included in this category it seems, as long as they maintain that it is this particular nature itself that is the cause of the activity from which we infer soul, rather than another substance or capacity capable of existing by its own.


In Nat. Hom. 51.9-10 Mewaldt (= xv. 97 Kühn), Galen refers to QAM’s λόγος φυσικός as having no little plausibility (οὐ σµικρὰν ἔχων πιθανότητα). Nemesius’ analysis of Galen (with what looks like reference to QAM, cf. Sharples and van der Eijk 2008 ad loc.) might be close our reading: he did not make a decisive or definitive statement on the soul, but it seems as if he considered it a mixture (NH 2, 23.24-24.4 Morani): Γαληνὸς δὲ ἀποφαίνεται µὲν οὐδέν, ἀλλὰ καὶ διαµαρτύρεται ἐν τοῖς Ἀποδεικτικοῖς λόγοις ὡς οὐδὲν εἴη περὶ ψυχῆς ἀποφηνάµενος· ἔοικε δέ, ἐξ ὧν λέγει, δοκιµάζειν µᾶλλον τὸ κρᾶσιν εἶναι τὴν ψυχήν (ταύτῃ γὰρ ἐπακολουθεῖν τὴν τῶν ἠθῶν διαφοράν), ἐκ τῶν Ἱπποκράτους κατασκευάζων τὸν λόγον.


The research which resulted in this paper has been made possible through a grant from the Netherlands Organization for Scientific Research (NWO) for the project ‘Human Nature: Medical and Philosophical Perspectives in the Work of Galen of Pergamum’.

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