Galen of Pergamum (129–c.215 AD) is still mostly known for his medical works, though the philosophical value and depth of his writings has come to be appreciated better in recent decades. New editions and translations of Galen’s work are appearing by the year and recent volumes such as Galien et la philosophie, Galen and the World of Knowledge and Philosophical Themes in Galen testify to the growing interest in Galen’s work as not only a valuable source for the study of ancient thought and philosophy in general, but as an interesting thinker in his own right.¹

The aim of this book is to build further on this recent work and contribute to the understanding of Galen’s thinking, with a particular focus on his views on the nature of man and the relation between body and soul. These subjects are arguably among the most interesting from a philosophical perspective on Galen’s work. As a philosophically schooled medical practitioner who is both fully acquainted with the previous and contemporary philosophical tradition as well as thoroughly experienced with the intricacies of the human body, and as a scientist keenly interested in the physiological underpinnings of the human psyche, Galen has unique contributions to these subjects.

Galen’s work is voluminous, complex and diverse. His scope, discerning scepticism, eclectic tendencies, his pragmatic approach with regard to the specific and varying aims of his writings, and last but not least his scornful attitude towards dogmatism and his refusal to adhere to any particular philosophical school – all of these make ordering his entire work into a systematic ‘philosophy of Galen’ an ungrateful task bound to encounter innumerable complications and likely to produce simplifications. Besides these complicating factors, there is also the sheer volume of Galen’s work. According to Jouanna, Galen’s work ‘comprises more than ten percent of all Greek literature that has survived from Homer to the end of the second century AD’.² Quite a few of these works, moreover, have not (yet) been translated into a modern language.

For these reasons, the methodological approach I have taken in this dissertation is as follows. I have conducted four separate ‘Case-Studies’ concerned with the fundamental question: what is Galen’s view of human nature? This question is inextricably related, as we shall see, to the questions of the (substance) of the soul, and the relation between body and soul. These questions are the central theme connecting the case-studies together. Each individual case-study, however, begins from a different treatise or set of treatises to discuss these questions. I have selected these texts on the basis of the questions. That is to say, I have principally selected works in which Galen actually discusses the subject of the soul and human nature, in order to then relate his discussion of these questions to other relevant works or passages from other works, often with help of the TLG. In this manner, I hope to avoid a problematic over-systematization of Galen’s work, while at the same time making an attempt to do justice to the connections between some of his works that treat of human nature and the soul, as well as to their embeddedness in Galen’s general oeuvre.

In each of these four case-studies, I undertake a close analysis of a particular text or set of texts and aim for an understanding of Galen’s views on these subjects that is supported by other works. For example, when we close-read the treatise That the Capacities of the Soul Follow the Mixtures of the Body (QAM) in Case-Study I, it turns out that Galen develops a notion of soul as the form of a homoeomerous body there, which can only be understood against the background of the role of homoeomerous bodies in his general analysis of the human body, for which we need to consult other works. In this way, I hope to gain an understanding of the selected key-texts that is as rich and as informed by other Galenic works as possible, while at the same time guarding against over-systematization by taking a single text or limited amount of texts as a reference point, without claiming the conclusions with regard to this text or set of texts to be unqualifiedly valid for Galen’s work as a whole.

The case-studies offer philosophical perspectives on Galen’s work. By that I mean two different but related things: (1) I will depart from philosophical questions (what is Galen’s view on human nature, the soul and the relation between body and soul?) and (2) I will analyse Galen as a philosopher. By that I do not mean that I will not take Galen’s specific medical focus and background into account, which in any case seems impossible. Rather, this is a methodological point designed to deal with the aforementioned complexity of Galen’s work and to do justice to Galen’s own aspirations as a philosopher. Someone else might well take different perspectives on Galen, often even with regard to the same works. I believe that Galen’s work lends itself well to such various approaches, which may be viewed as complementary rather than contradictory in a similar way as Galen saw the study of philosophy and medicine as complementary rather than contradictory. When we are dealing with a body of work that by its very nature crosses the boundaries of genres, we should be careful not to reduce it to any of those preconceived genres in particular. Therefore, the word perspectives in the title of this dissertation may be considered equally worthy of emphasis as the word philosophical.

Some overlap between the different case-studies is unavoidable, since the general questions underlying them are the same and since some passages in Galen’s work are crucial for an understanding of several of the key-texts which I discuss. In all case-studies, I undertake a close-reading of the relevant texts, which takes the form of quotations from and subsequent discussions of Galen’s text.

The first case-study starts with QAM, since Galen appears to be much more open to discuss the issue of the substance of the soul there than anywhere else. Moreover, Galen bases his discussion of the soul in QAM on some of his earlier works, as I hope to show. Therefore, it makes sense to begin with QAM and then see how it relates to the rest of the Galenic corpus. In QAM, Galen enters somewhat more speculative philosophical terrain and uses his general physiological framework, developed in works such as On the Elements According to Hippocrates (Hipp. Elem.), to argue not merely for the thesis ‘that the capacities of the soul follow the mixtures of the body’, but also for the stronger thesis that the substance of the soul is a specific mixture of the four elemental qualities.

This apparently rather physicalist position has been found problematic by scholars, both because of its supposedly radical reductionism and because Galen has quite consistently expressed his ignorance with regard to the substance of the soul elsewhere. Therefore, it has been argued that this stronger thesis was not actually held by Galen or in any case should not be taken seriously. This, in admittedly broad strokes, is the position taken by Donini, Garcia-Ballester, Lloyd and Singer.³ However, as I hope to show, a close-reading of the text that takes into account its relation to other Galenic work will add significantly to our understanding of QAM as a treatise that is, indeed, more experimental and speculative, but still firmly based in Galen’s own work. For this analysis I build on the previous work by Hankinson, Tieleman and Vegetti.⁴ I argue that Galen, through an integration of his Platonic-Hippocratic tripartition and trilocation of the soul with an Aristotelian hylomorphist notion of the soul as form of the body, together with his fundamental assumption that the nature or substance of beings is to be found at the most elemental level of their constitution, works out a notion of the substance of the soul as a specific mixture of elemental qualities that is in strong agreement with much of his other works. In this case-study on QAM I take up its stronger thesis in particular, in order to see to what extent Galen is committed to it, how he understands it and what he regards as its consequences for the possibility of ethics and self-amelioration. The latter part is important, since Galen himself presents his work in QAM explicitly as being ‘beneficial for those who wish to improve their soul’⁵ and since it has been suggested that Galen’s views in QAM rather amount to a kind of determinism and a rejection of free will.⁶ In this regard, I argue that Galen reserves a special place for the rational part of the soul in his discussion. He argues that the rational soul is a mixture as the other parts of the soul are, but also ascribes to this particular mixture a creative capacity that could be viewed as a likeness to the creative capacity of divine nature. In this likeness to divine nature lies the possibility for a philosophical life.

The second case-study will focus on Galen’s commentary on the Hippocratic On the Nature of Man, which is quite understudied compared to other Galenic works, perhaps because no good translation of it has been published yet (though this will soon change with the appearance of Jim Hankinson’s new translation in the Galen on Human Nature volume edited by Singer and van der Eijk). It is a key-text for Galen himself, clearly, since he presents this commentary as a more accessible follow-up on his Hipp. Elem., an earlier work which was written for an audience already familiar with some of his views and arguments.⁷ That is to say: with this work Galen undertakes a non-specialist exposition of his basic views on (human) nature, which makes it one of the most suitable texts for our purposes here. The word ‘human’ is bracketed in the previous sentence because the commentary is in fact concerned with the nature of all beings, rather than merely or specifically with the nature of human beings. The work shows much similarity to QAM, since it develops a notion of a hylomorphic primary substance as the common nature of all beings, consisting of a mixture of the four elemental qualities (the form) in a matter without quality in itself. It is also rather different from QAM, since the soul seems to be almost entirely absent from it. Why it is that the soul is not discussed by Galen in this treatise and how that fact relates to his notion of human nature as a hylomorphic substance, will be our main question in discussing this treatise.

In his commentary, Galen puts much emphasis on the right method for uncovering the common nature of things: a method of analysis, or division until no further division is possible. Again, it will turn out that in order to know what something is, we need to analyse its smallest constituent parts. Galen presents this method of division as a kind of Hippocratic-Platonic concord: Hippocrates used this method to discover the nature of the body and Plato stated that the same method must be used to discover the nature of the soul. I argue that Galen, as he does elsewhere, presents his own work as a Hippocratic-Platonic synthesis, which does not merely take either the nature of the body or the nature of the soul into account, but instead, using his Aristotelian hylomorphic perspective, develops a notion of the nature of ‘the whole’ in which the two are integrated.

In this case-study, I build on the work of Hankinson, Kupreeva, Tieleman and van der Eijk, in order to develop a new interpretation of Galen’s commentary.⁸ I also relate the concept of nature that we can derive from HNH to my analysis of QAM in Case-Study I.

In the third case-study, I delve into Galen’s dealings with Plato’s Timaeus, which must have been one of his favourite works. The Timaeus recurs often in Galen’s writings on human nature and the soul and must have played a fundamental role in the development of his views on these subjects. In his interpretation of the Timaeus, Galen develops what I would call a ‘somatisation’ of the soul, or more specifically: a recasting of the Platonic opposition between body and soul into an opposition between different elemental qualities. Therefore, his several writings on the Timaeus, namely his commentary and summary as well as the interpretations put forth in PHP and QAM, form a good follow-up on the two previous case-studies, in which we find that Galen develops a notion of the nature of man or the nature of the soul of man as constituted by specific mixtures of the elemental qualities. I shall argue that Galen’s often quite idiosyncratic interpretation of the Timaeus is an attempt to anchor this notion of the nature of man in the work of Plato. This perhaps comes to the fore most clearly in his interpretation of the metaphor of the river, which Timaeus uses to describe the confusion to which the soul is subjected upon its union with the body, but which Galen interprets as a kind of allegorical description of the predominance of wetness as one of the four elemental qualities making up the hylomorphic substance of the body. In this way, one of the elemental qualities which constitute the body comes to take over the role that the body as a whole plays in Plato, so that other elemental qualities which are opposed to it, dryness and heat, come to be associated with the soul as the Platonic antagonist of the body.

An important part of this case-study deals with the contested and therefore almost completely neglected fragments published by Carlos Larrain in 1992.⁹ Larrain thought these fragments were excerpts from the first two books of Galen’s commentary on the Timaeus but his view has been problematized by Diethard Nickel.¹⁰ More recent research by Aileen Das, however, suggests that a ‘re-evaluation’ of the status of these fragments is needed.¹¹ I start from the observation of some general tendencies in Galen’s interpretation of the Timaeus as we find it in his attested work, to then compare and see how Larrain’s fragments relate to the attested work. Larrain’s fragments are particularly suitable for such comparison in the context of this book since they often display the same ‘somatising’ tendency we find in some of Galen’s attested work on the Timaeus and which accords well with the findings of the first two case-studies. This case-study develops new insights with regard to Galen’s interpretation of the Timaeus, provides a much needed contribution to the study of Larrain’s fragments and their relation to the attested Galenic corpus, and relates its findings back to those of the two previous case-studies. Systematic study of Galen’s dealings with the Timaeus is scarce, but the work of Aileen Das and Mario Vegetti in particular provides a point of departure.¹²

In the fourth and final case-study I shall analyse Galen’s notions of black bile and melancholy. I have chosen to focus on black bile and melancholy to explore the relation between body and soul in Galen through a more concrete theme and to see whether Galen’s views on the nature of man and the nature of the soul, as they emerged from the previous three case-studies, find any concrete application when we look at a specific affliction of the human body or soul. The subject of black bile and melancholy is eminently suited to this purpose, because it is not only fairly well documented in Galen, but also crosses and problematizes the boundaries between the physical and the mental.

Galen’s views on black bile and melancholy are to a large extent shaped by the previous medical and philosophical tradition, particularly by the Hippocratic Corpus, Aristotle and Rufus of Ephesus. In order to adequately understand and assess Galen’s views on the subject, therefore, a brief discussion of these precedents is required. In this way, we are also able to determine what is innovative about Galen’s writing on black bile and melancholy. For the discussion of Galen’s precedents I build on an excellent existing body of literature on the ancient history of melancholy, particularly by Flashar, Jouanna, Klibansky, Panofsky and Saxl, Kudlien, Pormann and van der Eijk.¹³

The main questions of this case-study will be: to what extent does Galen attempt to understand melancholy in terms of the (elemental) qualities of the substance of black bile? – how does the causation between body and soul or body and mind work in his analysis of melancholy? – how can black bile be both a natural or normal part of our body as well as a dangerous substance causing mental illness? – what factors cause the black bile to become so dangerous and how do they relate to its (elemental) qualities? – what therapies does Galen propose for melancholy and how do they relate to the (elemental) qualities of the black bile?

In treating these questions, I hope to provide more substance to the notion of the nature of man and the nature of the soul as it has been developed in the previous three case-studies by zooming into a more concrete theme. At the same time, I aim to contribute to the study of black bile and melancholy in Galen, a subject which has remained surprisingly understudied despite Galen’s lasting influence on humoural theory in general and the notions of black bile and melancholy in particular. In part, this relative neglect might be because scholars have thought that Galen did not provide innovative contributions to the ancient understanding of melancholy.¹⁴ We can assess the extent to which this is true by comparing Galen to his aforementioned precedents. As I hope to show, the importance of Galen’s contribution to the understanding of black bile and melancholy has been underestimated. Galen’s writings on black bile and melancholy are spread throughout several texts. The key-texts for this case-study are On Black Bile (At. Bil.), Galen’s commentary on the Hippocratic On the Nature of Man (HNH) and chapters 9–10 from book III of his On the Affected Places (Loc. Aff.). As in the previous case-studies, I interpret these key-texts by continuous comparison with other Galenic works.

I close the book with a brief general conclusion, in which I bring the results of the individual case-studies together.