Introduction
Both Plato and Aristotle describe sensible objects as a kind of mixture of elements (and their qualities), they both agree that bodies of living organisms and their parts come into existence and remain alive and healthy only as long as the elemental parts of their mixtures retain in a kind of balance, and they both typically use the terms (syn)krasis and (sym)metria when discussing these topics. The philosophic discussions of mixtures in Plato and Aristotle are commonly interpreted against the backdrop of pre-Platonic philosophy, especially Parmenides, Alcmaeon, Empedocles, and Democritus, while the Hippocratic precursors of the idea often remain unnoticed.1 This is unfortunate not only from the historical point of view, as it gives a false impression that Early Greek philosophy and medicine developed independently from each other, but also because it underestimates the value of the Hippocratic evidence for our understanding of Plato’s and Aristotle’s own accounts.
In this paper, I focus on the early history of the concept of a well-balanced mixture, which is denoted by the terms krēsis (or synkrēsis) and metriē (or symmetriē). In the first part, I make the case that this conception originated in a specific medical tradition, and that practically all non-medical evidence from the end of the fifth century BC employs the terminology in medical contexts or in analogy with medicine. In the second part, I focus on Plato and argue that he was not only well informed about the medical theory but also that he employed it occasionally in his own accounts and thus introduced it into philosophical discussion. In the remaining parts, I shall successively discuss all occurrences of krasis and synkrasis in Aristotle’s works and divide them thematically into three groups. I start with the relation between mixis and krasis (part 3) and then focus on the use of krasis in respect to health, environment and procreation (part 4). Finally, I discuss the concept of krasis in relation to blood, intelligence and soul (part 5). In these parts, I will explore the extent to which Aristotle draws on the medical theory and accommodates it into his own accounts, and also how much he innovates and broadens its scope of application.
1 Krasis before Plato
The ancient Greek term krasis derives from the verb kerannymi and refers to the tradition of mixing wine with water in order to make it a healthier, more drinkable and less harmful beverage.2 Homer already uses the verb in this context, although he never employs the noun krasis.3 And, apart from a limited number of medical texts and a few isolated occurrences of the expression in non-medical authors, the term krasis/krēsis (as well as synkrasis/synkrēsis) is almost entirely absent from pre-Platonic literature. It is extremely rare in Greek drama; one can find it neither in Herodotus nor Thucydides, nor in the Greek orators, such as Gorgias and Lysias. There is no reference to krasis in Plato’s “early” dialogues, and there is only one isolated occurrence in Xenophon.
Probably the earliest piece of evidence for krasis as a blend of wine and water is a fragment from Aeschylus describing libations of wine.4 There are also a few pre-Platonic passages in which krasis is used metaphorically (i.e., as something that is likened to the blend of wine and water): Sappho speaks about the krasis of “wealth and virtue”;5 Euripides about the synkrēsis of “good and bad deeds”;6 and Charmides in Xenophon’s Symposium about the krasis of young people’s beauty and the notes of music.7
The only possible pre-Hippocratic evidence for krasis (as a mixture in the human body) is Parmenides’ fragment B 168 and Empedocles’ B 22.9 There is no doubt that both philosophers played an important role in the pre-Platonic philosophy of nature and that they also considerably influenced (directly or indirectly) medical speculation on the concept of a balanced mixture. However, it should be noted that—apart from these exceptional fragments—Parmenides, Empedocles and other pre-Platonic philosophers did not use the term krasis but rather expressions like mixis, diakrisis and synkrisis.10 Moreover, in comparison with the Hippocratic authors, the exceptional two fragments neither attest to a specific concern with health and disease, food and environment, nor to the idea of balance. The only pre-Hippocratic evidence for the idea of healthy balance is Alcmaeon’s fragment DK 24 B 4, which defines health as isonomia of bodily dynameis. On the one hand, this fragment provides a unique precursor of the concept of balance and its prominent role in medicine before the Hippocratic authors. On the other hand, it neither articulates the theory in terms of krasis and sym/metriē11 or the technical terminology of the Hippocratic texts, nor does it suggest any relation between the human body and food, exercise, environment, and other features specific for the medical discussion or for Plato’s and Aristotle’s accounts of health and related topics.
Given the traditional connection of krasis with wine, in combination with the fact that wine mixed with other ingrediencies (such as water, honey, vinegar, etc.) was a widely used remedy in ancient Greek medicine,12 and also that both Plato and Aristotle use the term frequently in medical contexts, one may easily assume that the idea of health as krasis is inherent to Greek medicine in general and that it is commonplace in the Hippocratic collection. Nonetheless, it should be noted that out of the 60 or so treatises included in Littré, only six contain the term krēsis or synkrēsis13 and only five of them are generally agreed to precede or to be contemporary with Plato, namely Airs, Waters, Places, On the Nature of Man, On Regimen, On Ancient Medicine and the fifth book of Aphorisms. Significantly, all of them promote a dietetic approach to health and all connect krasis with the concept of “moderation” or “balance” (formulated in terms of metriē/symmetriē and metriōs/symmetrōs, occasionally also isomoiriē,14 but never with Alcmaeon’s isonomia15).
Krēsis/synkrēsis stands in the five Hippocratic texts as a technical term for a mixture of the opposite qualities (a) in the environment, (b) in food, (c) in the human body,16 or (d) in the soul.17 And although there is no agreement among them as to the number and nature of the elementary parts of human bodies (e.g., two elements in Vict.; two humours in Aer.; four humours in Nat. hom.; and the innumerably many qualities in the VM), they all work on the hypothesis (or criticize it, as does the author of VM) that all the various kinds and states of human bodies can be diagnosed as well as cured according to an excess or surplus of hot, cold, dry and wet.18 Some of the texts also contain the idea that both environment and regimen substantially influence and precondition our mental capacities and even characters.19 On Regimen, the most elaborate account of dietetics, integrates most of these aspects into one single theory, discussing mixtures within the body as well as within the soul and providing practical instructions on how to achieve the best possible conditions for our sense perception, memory and intellect.20
The impact of these new medical conceptions and terminology was almost immediate, supposing that most of the five Hippocratic texts can be dated between the middle and late fifth century BC.21 Probably the earliest non-medical evidence of krasis in the new sense is Prometheus Bound (a play attributed to Aeschylus in antiquity but nowadays generally considered spurious), which cannot be dated later than 430 BC.22 In the play, Prometheus proclaims his merit in showing mankind, who used to waste away “for lack of medicine (
Another early reflection of the medical discussion is attested in a fragment from Euripides’ lost play Phaethon,25 in which the main hero is advised not to enter the air (aither) of Libya, for the “mixture” (krasis) there is void of moisture. This clearly references the concept of krasis as employed in the medical accounts of climate and its impact on human health,26 especially in Airs, Waters, Places, which includes comprehensive discussions of the differences in the climate/weather (krasis) in different continents,27 at different places,28 and during different seasons.29
Thucydides, as mentioned above, never uses the term krasis, although on one single occasion, towards the end of the last, unfinished book 8 of his Histories, he does use the word synkrēsis in a reflection upon the constitution of the Five Thousand. At that time, Thucydides reports, Athenians enjoyed the best government that they ever had, for they had a “balanced mixture” (metria … synkrēsis) of the rich and the poor, i.e. of oligarchy and democracy.30 Although there is no explicit reference to medicine in the passage, the phrase “balanced mixture” itself may be informed by a specific concept of health that Thucydides uses to illustrate the healthy nature of the constitution under consideration.31 Given the fact that we can date Thucydides’ report between 411 and Thucydides’ death (perhaps 399–396 BCE), it is most probably the earliest non-medical evidence of the conjunction of sym/metriē and synkrasis,32 which defines the medical concept of “balanced mixture” in the Hippocratic On Ancient Medicine and On Regimen.33
2 Plato on Krasis and Symmetry
In contrast to the isolated references to the medical terminology in pseudo-Aeschylus, Euripides, and Thucydides, Plato is the first “non-medical” author to employ the terms krasis and synkrasis (in conjunction with metria and symmetria) on a regular basis, often explicitly in a medical context. Altogether, there are 17 occurrences of krasis and 9 of synkrasis in Plato’s dialogues. In addition, Plato also used (and possibly coined) the noun eukrasia (Ti. 24c6), which is unattested in the Hippocratic texts.34
In the Symposium, to start with Plato’s most explicit reflection on the medical theory, the physician Eryximachus suggests that “our very bodies manifest two species of love”, namely “love manifested in health” and “love manifested in disease” (186b5–6). Then he draws an analogy with music (187c4–5: “music is therefore simply the science of the effects of Love on rhythm and harmony”) and proclaims that the same principles must also be recognized in medicine and all other disciplines. “Even the seasons of the year exhibit their influence”, as he claims with the following explanation:
When the elements to which I have already referred—hot and cold, wet and dry—are animated by the proper species of Love, they are in harmony with one another: their mixture is temperate (
ἁρμονίαν καὶ κρᾶσιν λάβῃ σώφρονα ), and so is the climate. Harvests are plentiful; men and all other living things are in good health; no harm can come to them. But when the sort of Love that is crude and impulsive controls the seasons, he brings death and destruction. He spreads the plague and many other diseases among plants and animals; he causes frost and hail and blights.35
There is no doubt that Eryximachus reflects upon the specific medical tradition attested in the Hippocratic texts in which matters of health and prosperity (including fertility) on the one hand, and pain and disease on the other, are discussed in terms of a proportional or disproportional mixture of the elementary qualities, and special attention is devoted to the effects of environmental conditions on men, animals and plants.36
There are three occurrences of krasis in the Phaedo, one of which also discusses the blend of seasons. In the final myth, Socrates speaks about the inhabitants of a fictitious land with a climate of such a “mixture of seasons” (
Another remarkable use of krasis in the Phaedo is attested at the very beginning of the dialogue. Phaedo describes his mood during his last meeting with Socrates as “a strange feeling, an unaccustomed mixture (krasis) of pleasure and pain at the same time”,41 as he enjoyed the philosophical discussion but, at the same time, reflected that Socrates was about to die. This inconspicuous remark opens the discussion of the concept of mixture in the dialogue and also foreshadows the idea of mixtures of pleasure and pain in the soul and the body, discussed in detail in the Philebus.42
And finally, within the discussion of the immortality of the soul in the Phaedo, Socrates argues that the soul is akin to things that are unperishable, invisible, and divine. Simmias objects that “one might make the same argument about harmony, lyre and strings, that harmony is something invisible, without body, beautiful and divine in the attuned lyre”, and he therefore suggests that “the soul is a blend and harmony43 (
In the Timaeus (37a2–4, see also 43c7–e4), we read that the world soul “is blended (
Any kind of blend (
σύγκρασις ) that does not in some way or the other possess measure or the nature of proportion (μέτρου καὶ τῆς συμμέτρου φύσεως ) will necessarily corrupt its ingredients and most of all itself. For there would be no blending (κρᾶσις ) in such cases at all but really an unconnected medley (τις ἄκρατος ), the ruin of whatever happens to be contained in it.46
In summary, Plato in his late texts uses the terms syn/krasis and symmetria (as well as metriotēs and other terms for “right measure”) in a literal sense, i.e. as a physical and sensible mixture, and identifies the right measure as the essence of each and every mixture.47 This explains his confidence that “even physical entities can attain a relatively stable state”, as D. Frede (2017) fittingly remarks, suggesting that Plato was encouraged to embrace such theories “by the advances of astronomy and harmonics in his own lifetime”. As I have tried to substantiate so far, the specific use of krasis and related terminology in Plato’s texts clearly indicates that also medicine and especially dietetics (as represented in the five Hippocratic texts) must be added to the list of Plato’s sources of inspiration in matters of balanced mixtures.
3 Aristotle on mixis, krasis and the Generation of homoiomera
Altogether, there are 26 occurrences of krasis, two of eukrasia48 and one of synkrasis49 in Aristotle’s ‘genuine’ works.50 And most of them are related—directly or indirectly—to health and conditions of life and prosperity. As I shall illustrate in the following two sections (4–5), most of the occurrences can be divided into four groups that we already know from the Hippocratic texts and Plato: those referring to a blend (a) in the body (in general or in a specific part of the body), (b) in things that enter the body (i.e. the air, water, and nourishment), (c) in the environment, including weather conditions, seasons, and climate, and (d) in the soul.
Before we proceed to the particular passages, it is necessary to make clear that Aristotle distinguishes krasis from mixis, synthesis and other kinds of material compositions.51 According to his own standards, many of his predecessors (including Plato)52 used the terms mixis and krasis incorrectly and interchangeably, while others confused mixis (and krasis) with synthesis. Hence, on several occasions, Aristotle makes considerable effort to define these terms and to clarify the difference between them. In Topics, Aristotle makes the distinction between mixis and krasis one of his main examples of an incorrect use of terminology regarding the genus-species difference:
Further, you must see whether your opponent has placed the genus inside the species, taking, for example, contact as conjunction or mixture as blend (
μεῖξιν ὅπερ κρᾶσιν ), or, according to Plato’s definition, locomotion as impulsion. For contact is not necessarily conjunction … Similarly also with the other instances; for mixture is not always blend (οὔτε γὰρ ἡ μεῖξις ἅπασα κρᾶσις )—for the mixture of dry substances is not blend (ἡ γὰρ τῶν ξηρῶν μεῖξις οὔκ ἐστι κρᾶσις )—nor is locomotion always impulsion.53
This passage makes it sufficiently clear that krasis is a specific kind of mixis. Accordingly, mixis can be used as a generic name for krasis but not vice versa.
Aristotle’s specific understanding of mixis is discussed in detail in Generation and Corruption,54 in which he aims to explain how sensible natural objects in general (and homoiomerous parts of animal bodies in particular) come into existence out of the four elements and their qualities. In his review of previous theories, he pays special attention to the theories of Empedocles and the Atomists. Empedocles taught that “there is no origin of anything, but only a mingling (
Neither the atomistic theory of Leucippus and Democritus, which Aristotle acknowledges as the most advanced and consistent philosophical explanation concerning matter and the coming-to-be of sensible objects,58 succeeds to explain what happens when two or more components are mixed together. On this theory, “the primary bodies, from which originally bodies are composed and into which ultimately they are dissolved, are indivisible (adiaireta), differing only in structure (schēma)”.59 In other words, the atoms of the mixed substances remain intact and change only in respect to their relation with each other.60 Hence, it is wrong to say that “things have been mixed” when the things being mixed are preserved at the level of small particles. “For this will be composition (synthesis)”, explains Aristotle, “and not blend (krasis) or mixture (mixis), nor will the part have the same proportion (logon) as the whole”.61 “But we say”, clarifies Aristotle, “that if things have in fact been mixed (memiktai) the mixture has to be homoiomerous, and that just as a part of water is water so it is with what has been mingled”.62
After the thorough discussion of the shortcomings of the predecessors’ theories, Aristotle finally defines mixis in chap. 10 as “the union (henōsis) of mixables (miktōn), when they have undergone alteration”.63 And “mixable” is “anything which, being easily modified in shape, is capable of acting or being acted upon, and is mixable with something else of the same kind as itself”.64 Aristotle specifies that only materials that are easily divisible and modifiable in their form are capable of mixture, “since they divide easily into small parts, which is precisely what it is to be easily bounded; for instance, liquids are the type of bodies most liable to mixing; for liquids are the most easily bounded of divisible things, unless they are viscous (these have the effect only of multiplying and increasing bulk).”65 And since only a mixis of liquids66 can be properly called krasis,67 and given the fact that liquids are the most mixable of all bodies, krasis is the most perfect form of mixis.
It is critical to every mixis that each of its constituents brings a specific quality to their union. Accordingly, when many divided pieces are juxtaposed to a few or large ones to small, “then indeed they do not give rise to mixing”. “Thus a drop of wine is not mixed with ten thousand pitchersful of water, for its form dissolves and it changes into the totality of the water.” Nonetheless, as Aristotle stresses, “when the two are more or less equal (isazēi pōs) in strength (dynamesin), then each changes from its own nature in the direction of the dominant one, though it does not become the other but something in between (metaxy) and common to both (koinon)”.68
In the second book of Generation and Corruption, the concept of mixis plays a crucial role in Aristotle’s explanation of the transformation of elements from the opposite qualities and the generation of homoiomera and other compounds from the elements and their qualities.69 The elements are transformed when the hot and the cold mix together in such a way that they achieve some proportion (logos).70 And also other bodies result from a mixture of the contraries:
In this way what comes to be is a mixture (mixis), in that way it is matter. Since the contraries are also acted upon as stated in the definition in Book I […] first, the elements change in this way; but flesh and bones and suchlike come from these [elements], the hot becoming cold and the cold hot when they approach the mean (to meson), for here they are neither one thing nor the other, and the mean is large and not an indivisible point. Similarly dry and wet and suchlike produce flesh and bone and the rest in the middle range (kata mesotēta).71
Although the mean or proportion between the opposite qualities of the ingrediencies in the mixture has some extension, mixtures in general are essentially unstable and permanently susceptible to change, given the fact that it is characteristic for mixtures that they consist of substances that are easily modifiable and that the mixture of them must also be easily modifiable.72 And the same holds for blends, i.e., mixtures of liquids, the most modifiable and mixable of all bodies.73 Despite the fact that the term krasis is mentioned only once in Aristotle’s account of mixis in Generation and Corruption,74 in other works he strongly prefers it when speaking about mixtures in animal bodies (and their parts), in food or in the environment.75
4 Aristotle on Health, Environment and Procreation
In Topics, Aristotle defines health as a symmetry (symmetria) between the hot and cold qualities (in the body),76 while in Physics he describes it in terms of krasis and symmetria:
Thus bodily excellences such as health and fitness (
ὑγίειαν καὶ εὐεξίαν 77) we regard as consisting in a blending (ἐν κράσει ) of hot and cold things78 in due proportion (συμμετρίᾳ ), in relation either to one another within the body or to the surrounding.79
Given the fact that the proportion between the hot and cold (and, accordingly, also dry and moist)80 in the body is not fixed (for it is neither the same in all human bodies nor always the same in one individual),81 the bodily equilibrium is delicate and vulnerable. Not only are there people of inherently unstable krasis (such as melancholics, who need permanent medical attention, “because their krasis keeps their bodies in a constant state of irritation, and their appetites are continually active”),82 but also individuals with a relatively healthy constitution and stable krasis who are under permanent threat of losing the healthy balance when exposed to an imbalanced climate, seasonal changes or unhealthy regimen. As for the climate and seasons, our sense of hearing, for instance, is impaired “during damp seasons and in damp climates (
Aristotle is perfectly in line with the Hippocratic authors in all these accounts of health,85 and it seems obvious that he uses the dietetic terminology (krasis, symmetria) in the same way as his medical forerunners.86 In regard to his confidence in the medical concept, it is no surprise that he recommends his readers to follow doctors’ instructions in matters of healthy diet87 as well as in matters of procreation.88 However, it is remarkable that, apart from these definitions and occasional remarks on health, he rarely speaks about specifically medical topics or about the effects of seasonal changes or extreme environmental conditions on the body of individual men or women.89 Instead, Aristotle employs the dietetic terminology in his environmental explanations of the variations among animal species and populations regarding their natural habitat, nourishment, fertility, longevity,90 differences in sizes, and other remarkable features of their bodies and lives.
In Hist. an. 7/8, Aristotle holds that animals in general “differ according to localities (topous)”, and explains that “just as in some places certain animals do not occur at all, so in certain places they do occur but are smaller and shorter-lived and do not thrive.”91 For instance, some animals are larger in Egypt than in Greece, such as cattle and sheep, some are about the same, for example crows and goats, and some are smaller, such as wolves and asses and hares and foxes and ravens and hawks. For these differences Aristotle suggests the following explanation:
The cause is said to be the food (tas trophas), in that it is unstinted for some but scanty for others … in many places the climate (krasis) too is a cause,92 for example in Illyria and Thrace and Epirus the donkeys are small, while in Scythia and the Celtic country they do not occur at all; for these animals winter badly.93
Apart from variations in size, different localities also produce “difference in character”: “for example mountainous and rough places produce character different from those in level and soft places: even in their look they are wilder and fiercer” (7/8.29, 607a9–12). And in general, “the wild (agria) animals are wilder (agriotera) in Asia, but those in Europe are braver (andreiotera), while those in Libya are most varied in form”, holds Aristotle with a reference to a proverb that “Libya ever bears something new”.94
It should be emphasized that, in these passages, Aristotle ascribes the same environmentally conditioned characteristics to wild animals as the author of the Hippocratic Aer. ascribed to various human tribes and nations of Europe, Asia, and Libya.95 And the delicate connection between the blends in animal bodies, food, and environment, which is discussed in detail in the other Hippocratic texts (esp. On Regimen and On the Nature of Man), is taken into account in Aristotle’s distinction between land and water animals in Hist. an. 7/8. 2:
But we speak about this difference [i.e. the difference between land and water animals] in two ways: (i) some are called land or water animals because they take in air or water respectively; (ii) others, not taking it in but being satisfactorily constituted naturally in relation to the blend of cooling (
πρὸς τὴν κρᾶσιν τῆς ψύξεως ) that is found in the one or the other element, are called land or water animals not because they breathe air or take in water but in virtue of feeding and living in the one or the other.96
After having discussed water animals in the primary sense, i.e., according to what they take in (air or water) for the sake of cooling, Aristotle turns to the second aspect of the division and makes it clear that there is a close relation between the species-specific krasis and the quality of food appropriate to the dietetic needs of the species:
Those that are water animals in the second way, that is, because of their blend and their life (
διὰ τὴν τοῦ σώματος κρᾶσιν καὶ τὸν βίον ), include all that take in the air but live in the wet, or take in the wet and possess gills but go on to the dry and get food.97
In his concluding summary of this discussion, Aristotle enumerates three aspects of the distinction between the land and water animals (“by taking in air or water, and by their bodily blend [krasis], and thirdly by their feeding”) that allow him to identify two approaches to the distinction: (i) those who follow blend, feeding and taking-in, and (ii) those that follow blend and feeding alone.98
In Gen. an., book 4, the nutritive and environmental conditions are discussed with regard to fertility and procreation. In the following passage, for instance, Aristotle brings together the condition of the body with the quality of the air, food, and water:
Also, one country differs from another in these respects, and one water from another, on account of the same causes, for the quality of the nourishment especially and of the bodily condition (
τοῦ σώματος ἡ διάθεσις ) of a person depends upon the blend of the surrounding air (διά τε τὴν κρᾶσιν τοῦ περιεστῶτος ἀέρος ) and the foods which the body takes up, and especially upon the nourishment supplied by the water, since this is what we take most of, water being present as nourishment in everything, even in solid substances as well. Hence hard, cold water in some cases causes bareness, in others the births of females.99
The question of procreation is further discussed a few pages later when Aristotle speaks of the periods suitable for procreation and draws his argument from the assumption that the symmetry between hot and cold is vital for all kinds of procreation (“it is heat and cooling in their various manifestations which up to a certain due proportion [
It is no coincidence that the fundamental assumption (that nothing comes into being and exists without some sort of symmetry within a mixture of opposite but complementary elements or/and their qualities) is mentioned in all five Hippocratic texts that contain the term syn/krasis.101 In the Hippocratic Aphorisms, for instance, we read that only those women who “have a just blend (krasin symmetron)” of hot, cold, dry, and moist elements in their body (Aph. 5.62 = L 4.556) can conceive. The author of Aer. 5 describes the condition of a city oriented eastwards and holds that it is like spring, “because the heat and the cold are tempered (kata tēn metriotēta)”, that the diseases in the city are “fewer and less severe” than in a city oriented to the south, and that “women there very readily conceive and have easy deliveries”.102 Probably the most complex formulation of the idea is provided by the author of On the Nature of Man in his attack against monism:
Moreover, generation will not take place if the combination of hot with cold and of dry with moist be not tempered and equal (
μετρίως πρὸς ἄλληλα ἕξει καὶ ἴσως )—should the one constituent be much in excess of the other, and the stronger be much stronger than the weaker. Wherefore how is it likely for a thing to be generated from one, when generation does not take place from more than one unless they chance to be mutually well-tempered (κρήσιος τῆς πρὸς ἄλληλα )?103
5 Aristotle on Blood, Intelligence, and Soul
The most obvious bodily part that can be described and analysed in terms of krasis is the blood, “the most indispensable and most universal” part of blooded animals,104 the final form of nourishment and the material principle of reproduction.105 In a sense, “blood is the matter of the entire body; for nourishment is matter, and blood is the last stage of nourishment.”106 And there are great variations in the quality of this vital liquid: “it can be thin (
Given the fact that blood is the final form of nourishment, its quantity as well as quality depend on what one eats and drinks: “This explains why the blood diminishes in quantity when no food is taken and increases when it is; and why, when the food is good, the blood is healthy, when bad, poor”.108 In addition to food, the operation of various internal organs also influences the quality of blood, such as the blood vessels (including the heart, “the source of blood”, and “the primary blooded part”),109 the liver, and the gallbladder. In Part. an. 3.12, Aristotle explains the fact that some viviparous animals have both liver and gallbladder while others have only a liver as follows:
This is also why some of the live-bearing animals have no gallbladder; for the liver contributes considerably to the proper blend and health of the body (
πρὸς εὐκρασίαν τοῦ σώματος καὶ ὑγίειαν ); for their end is present most of all in the blood, and the liver is, after the heart, the most bloody of the viscera. The livers of most of the four-footed egg-layers and fish are yellowish, and those of some are in fact completely foul, even as their bodies have taken on a foul blend (φαύλης κράσεως ), e.g. the livers of toad, tortoise, and other such animals.110
Apart from health, “the nature of blood is the cause of many features of animals with respect to both character and perception”,111 as we can see, for instance, from Aristotle’s account of the brain. The brain is the coldest of all the parts in the body112 and its main function is “to counterbalance the region of the heart and the heat in it”.113 Hence, it is the brain that “makes the heat and the boiling in the heart well-tempered (metrias thermotētos)”.114 Yet, in Part. an. 4.10, Aristotle introduces an additional function to the brain:
The head is present above all for the sake of the brain; for the blooded animals must have this part, and in a place opposite the heart, owing to the causes stated previously. And nature placed some of the modes of perception on the outside of it as well, on account of the blend of the blood being well proportioned (
διὰ τὸ σύμμετρον εἶναι τὴν τοῦ αἵματος κρᾶσιν ), i.e. adapted for the warmth of the brain and for the quietness and accuracy of perception.115
Accordingly, the optimal condition for the performance of the sensory organs in the head is relatively colder than the optimal condition of blood in the heart.116 But it should not be too cold either, because “when the parts around the brain are colder than the well-proportioned blend (
In addition to health and sensation, the quality of blood also influences one’s character, physical strength, intelligence, and emotions. “Thicker and hotter blood is more productive of strength, while thinner and cooler blood is more perceptive and intelligent”.118 Best of all are animals “with hot, thin, and pure blood, for such animals are at once in a good state relative to both courage and discernment.”119 On the other hand, the animals that have exclusively watery blood are more timid:
This is because fear cools; accordingly, those having such a blend in the heart (
ἐν τῇ καρδίᾳ κρᾶσιν ) are predisposed to this affection, since water is solidified by the cold. This is also why the other bloodless animals are, generally speaking, more timid than the blooded, and when afraid become immobile, discharge residues, and in some cases change their colours.120
Other emotions can also be related to the quality of the blood: as fear cools it down, passion (thymos) produces heat in it (650b35–36). And anger, as we know from On the Soul, can be defined as “a boiling of the blood and heat surrounding the heart”.121
In these accounts on blood, Aristotle evidently draws on two conceptions developed already by his predecessors: the concept of balanced mixture identified with the soul, and the idea that blood is causally connected with sense perception, thinking, and soul. In On the Soul, Aristotle attests that some of his predecessors identified the soul with the blood, such as Critias, who supposed that “sensation is the peculiar characteristic of the soul, and that this is due to the nature of blood”.122 Hippo, on the other hand, rebutted those “who say that the soul is blood, on the ground that the seed is not blood; and seed, he says, is primary soul”.123 Some of the Hippocratic authors also presupposed a strong connection between blood, perception, and thought, such as the author of Diseases in his aitiology of phrenetis,124 or the author of On Breath in his account of the so-called “sacred disease” and its causes.125 There is a certain link between blood and thinking in On Regimen as well, for instance when the author suggests that an inflammation of the blood can cause madness of the soul.126 Yet, despite the fact that these passages confirm a close relation between blood and intelligence (or soul), there is no explicit Hippocratic evidence that it is the krasis of the blood that influences the sensation and thinking. The application of the specific concept of krasis in the account of blood seems to be Aristotle’s novelty.
Concerning the concept of krasis and its relation to the soul, Plato’s Socrates was already confronted with the view that the soul is a kind of blend or harmony between the hot, cold, dry, and wet, which are mixed with each other “rightly and in due measure” (Phd. 85e3–86c2). Aristotle in De an. 1.4 mentions the same idea (“the soul is a kind of harmony, for harmony is a blend or composition of contraries [
There is no doubt that both Plato and Aristotle understood this materialistic theory of the soul as a respected rival theory that deserves special attention.129 Moreover, Aristotle’s own conception of the soul as the form of the living body is in some respects very similar to the concept of harmony/krasis.130 And although he eventually admits that it is appropriate to employ this concept in accounts of health and excellences of the body,131 he holds it inappropriate for discussions on the soul. He distinguishes between two versions of the conception, both of which can easily be disproved: (a) that the soul is a composition (synthesis) of the bodily constituents, and (b) that the soul is a certain proportion (logos) of the constituents.132 The latter one must be disproved because “the mixture of the elements which makes flesh has a different ratio from that which makes bone”. “The consequence of this view will therefore be”, Aristotle infers, “that distributed throughout the whole body there will be many souls, since every one of the bodily parts is a mixture of the elements, and the ratio of mixture is in each case a harmony, i.e. a soul”.133
In regard to the idea that the soul is a composition (synthesis), Aristotle finds it absurd because “there are many and various compoundings of the parts”.134 Aristotle’s point is that there are various ways in which materials are combined in animals and their parts and that they cannot be all reduced to one overall krasis. For the same reason, Aristotle in Metaphysics 8.2 criticizes Democritus for reducing the variety of material forms to differences in shape, position, and arrangement of the atoms. “But evidently there are many differences”, Aristotle objects, “for instance, some things are characterized by the mode of composition of their matter, e.g. the things formed by blend (krasei), such as honey-water, and others by being bound together, e.g. a bundle; and others by being glued together, e.g. a book; and others by being nailed together, e.g. a casket; and others in more than one of these ways …”135 And the same holds also for the parts of animal bodies, especially the anhomoiomerous parts, such as hand or foot:
And the being of some things will be defined by all these qualities, because some parts of them are mixed (memichthai), others are blended (kekrasthai), others are bound together, others are solidified, and others possess the other differentiae; e.g. the hand or the foot. We must grasp, then, the kinds of differentiae, for these will be the principles (archai) of the being of things […].136
Conclusion
In a well-known and much discussed passage closing Parva Naturalia, Aristotle acknowledges that there is an overlap between natural philosophy and medicine. He admits that “the more subtle and inquisitive” doctors “have something to say” about natural science, and claims that “the most polished of those who study nature [i.e., philosophers] end up by considering medical principles (archai)”.137 In my analysis, I aimed at illustrating that the concept of a well-balanced krasis provides us with one of the best documented examples of a principle (archē) of medical origin that was carefully considered and even adopted (with emendations, extensions, or limitations) by the most polished natural philosophers, such as Plato and Aristotle.
I made the case that Plato belongs to the first generation of authors who reflect upon the new medical concept and terminology. In some of his accounts of the nature of material structures (i.e., Ti. and Phlb.), he even makes krasis (and/or symmetria) one of the most fundamental principles of material structures. Although he refuses the idea of the soul as a krasis of bodily constituents, he occasionally employs the specific terminology in his discussions of the soul and caring for it. Unlike Aristotle, Plato uses the dietetic terminology (syn/krasis, kerannymi) rather loosely, sometimes interchangeably with mixis (and meignymi). However, he can probably be credited with the medical concept gaining full recognition in philosophical discussions.
Aristotle, on the other hand, employs the medical vocabulary mostly in perfect accordance with the Hippocratic authors. Throughout his biological works, he agrees that the condition in which the bodily constituents are blended together in due proportion and in which its opposite qualities counterbalance each other is the best one, the healthiest, and most optimal for procreation and many other natural activities, including perception and thinking. Nonetheless, Aristotle also develops the theory further and adjusts it to his own methodological framework, for instance when he defines krasis (as a specific form of mixis) against other forms of material arrangements and thus confirms its status as a terminus technicus and one of the most important principles of natural science. Moreover, his definition includes the concept of homoiomerity (as a necessary condition of each and every mixis), which paves the way for his own explanation of how homoiomerous parts in general, and those of animal bodies in particular, come into existence out of the elements and their qualities. Aristotle’s second addition (and innovation from the perspective of natural science) consists in the transposition of the dietetic principles from human individuals and populations to other zoological species and their specific bodily designs (which are presupposed to be adapted to specific environmental conditions, climates, kinds of nourishment, etc.). And thirdly, Aristotle shifts the focus from the body as a whole (as was the standard perspective in the Hippocratic texts) to the particular bodily parts and organs and their mutual cooperation, most significantly to the blood as the most vital bodily fluid, and to the heart as the most vital bodily organ.
Five centuries later, Galen opens his own account of the topic in On Mixtures (Peri kraseōn) with the assumption that it “has been adequately demonstrated by men of ancient times, the best of both philosophers and doctors” that the bodies of animals “consist of a mixture (
E.g. Hershbell (1983), Wright (1990) 217, Hussey (2006) 17, Sassi (2015), Gulley (2017). See also Jouanna (2002) 256. The significance of the Hippocratic evidence has been noticed by Peck (1937) 37–39, (1942) lv–lvii, (1965) lxxv–lxxvii, and Tracy (1969) 32–76, and most recently revisited by Mirrione (2021), Popa (2014) and (2021), Morel (2021), and Bartoš (2021) 51–53. All translations are listed in the ‘Texts and editions used’.
Cf. Plato, Leg. 773d1–4, Xenophanes DK 21 B 5, and the Hippocratic VM 20 (I.622 L. = 52,2–4 Heiberg).
See Montanari (1979) 99–104, and Sassi (2015) 11.
Aeschylus (Tetralogy 9, play A, fr. 67,12, ed. Nauck).
Sappho, fr. 148,2 (ed. Lobel-Page).
Euripides, Aiolos, fr. 21,4 (ed. Nauck).
Xenophon, Symp. 3,1.
Parmenides DK 28 B 16: “
Empedocles DK 31 B 22. It should be noted that Aristotle never ascribes krasis to Empedocles. In all passages quoting, referring to, or criticizing his theories, Aristotle consistently uses the term mixis (e.g. Part. an. 1.1, 642a17–22, De an. 1.4, 408a13–23).
Cf. Parmenides DK 28 B 8,27–28; Empedocles DK 31 B 8 and A 40; Anaxagoras DK 59 B 4 (symmixis). See also Aristotle Gen. corr. 2.6, 333b13–20, quoted below, p. 80.
Cf. Sassi (2015) 11: “One must note, however, that the use of krasis to explain the concept of isonomia in the context of this fragment belongs to the doxographer.” See also Kouloumentas (2014). The same applies to the use of krasis/krēsis in Theophrastus’ reports on Democritus’s explanation of thought (Sens. 58) and Diogenes’ account of perception (Sens. 39).
Cf. Lonie (1977). See also Aristotle Gen. corr. 1.7, 324a29–30: “for we speak of the doctor, and also of wine, as healing”.
According to the analysis by W. Smith (1992) 270–271, there are 27 occurrences of the terms krēsis and synkrēsis in the Corpus Hippocraticum, 19 of them in On Regimen (all in book 1), five in On Ancient Medicine, two in On the Nature of Man, and one in Airs, Waters, Places. There are two passages omitted by Smith, one in Aphorisms (Aph. 5.62.5, IV.554–556 L.), which seems to draw on On Regimen (especially chap. 37), and another in On Sevens (Hebd. 24, VIII.647.25–26 L.). Given the disputable date of Hebd., it will not be taken into consideration in this chapter.
E.g. Aer. 12 (II.54.3 L. = 54,16 Diller).
Cf. Kouloumentas (2014) 872.
Cf. Aer. 12 (II.52.19 L. = Diller 54,13); Nat. hom. 3 (VI.38 L. = 172,1 Jouanna); Aph. 5.62 (IV.556 L.); VM 5 (I.582 L. = 39,22 and 24 Heiberg) and VM 16 (I.606 L. = 47,15 Heiberg).
E.g. Vict. 1.7 (IV.480 L. = 130,18–20 Joly-Byl), 1.25 (VI.496 L. = 142,6–8 Joly-Byl), 1.35 (VI.512 L. = 150,29–31 Joly-Byl).
In line with the original meaning of kerannymi (which derives from the ancient custom of tempering the strong potency of wine with the weak potency of water, or hot water with cold water), krasis in Hippocratic texts can be seen as a procedure (as well as its result) by which the physician mixes the qualities of different strong and weak substances in order to obtain a moderate qualitative average between the two extremes. See Festugière (1948) 37–38, Tracy (1969) 37–38, and Mirrione (2017) 19–20.
VM 10 (I.595 L. = 42,22–25 Heiberg) and Vict. 1.35–36. See also Prorrh. (2.4, IX.14.16–23 L., and 2.12.22, IX.34.11–13 L.), and Aff. 46 (VI.254.16–18 L.).
Vict. 1.35–36. E.g. Vict. 1.36 (VI.522 L. = 156,19–20 Joly-Byl): “It is this blending (synkrēsis), then, that is, as I have now explained, the cause of the soul’s intelligence or want of it”.
For approximate dating of individual Hippocratic texts, see Jouanna (1999) and Craik (2015).
Prometheus Unbound (a part of the same trilogy as Prometheus Bound) was parodied in Cratinus’ Ploutoi (429 BC), and Prometheus Bound in Cratinus’ Seriphioi (c. 423) as well as in Aristophanes’ Acharnians (425 BC). See West (1990) 65.
Aeschylus, PV 476–483.
This terminology is best documented in On Ancient Medicine (5, I.580–582 L. = 39,6–26 Heiberg).
Euripides, Phaethon, fr. 779,2 (ed. Nauck).
E.g. Vict. 2.38 (VI.532 L. = 160,22–26 Joly-Byl), tr. Jones: “in the most adjacent countries it [i.e. the sun] must impart such a hot and dry quality, as it does in Libya, where it parches the plants, and insensibly dries up the inhabitants.”
Aer. 12 (II.52–54 L. = 54,10–17 Diller).
Aer. 5 (II.24 L. = 32,20–24 Diller). See also Vict. 2.37.
Aer. 10 (II.42 L. = 46,16–22 Diller).
Thucydides Hist. 8.97.2.6–7 (ed. Jones-Powell).
Thucydides is most probably the very first non-medical author who recognizes dietetics as a specific medical approach, different from other means of therapy (Hist. 2.51.3), cf. Bartoš (2015) 37–38.
Cf. Rocher (1994, 41): “The political pattern, which is implicit in the text of the great Athenian historian, is compared to the paradigms of perception fitness in the fifth century views of cognition, and of health in Hippocratic medicine”.
The term synkrēsis is attested once in VM (24, I.634 L. = 55,8 Heiberg) and seventeen times in Vict. (especially in ch. 32, 35, and 36).
Nonetheless, the Hippocratic authors already occasionally use the adjective eukrētos, e.g., Aer. 24 (II.90 L. = 80,9 Diller) and Vict. 3.68 (VI.600 L. = 198,10–11 Joly-Byl).
Symp. 188a4–b3, tr. Nehamas and Woodruff. See also Symp. 186d5–e3.
Craik (2001) and Thivel (2004) argue specifically for Vict.; Vegetti (1995, 69–70) for Aer. and Epidemics I. Most recently, Marino (2016, 241–252) makes the case that Plato draws on the Hippocratic VM, De arte, Flat. and Vict. See also Edelstein (1945).
Phd. 111b1–6.
Ti. 24c4–7. In terms of the impact of a balanced climate on human character, the author of Aer. holds that Europeans are more courageous than Asiatics because in Europe there are greater variations of seasons while the climate in Asia is mild and free of changes: “for uniformity engenders slackness, while variation fosters endurance in both body and soul; rest and slackness are food for cowardice, endurance and exertion for bravery” (Aer. 23, II.84 L. = 76,22–78,1 Diller, tr. Jones).
E.g. Cri. 111e4–5, Plt. 272a6–b1, Phlb. 26a6–b1, Epin. 976a1–4.
The author of Aer. makes the case, for instance, that the persons of the inhabitants [of a city oriented eastward] are “of better complexion and more blooming than elsewhere”, and that “they are clear-voiced, and with better temper and intelligence (xynesin) than those who are exposed to the north” (Aer. 5, II.22–24 L. = 32,1620 Diller, tr. Jones). In On Regimen, we find the idea that seasons (as well as all other external sources of hot, cold, dry, and wet) directly influence not only our health but also perception, cognition, and memory. In ch. 35, the author discusses seven types of fire-water krasis in the soul and for each type suggests what to do or avoid during each season of the year.
Phd. 59a1–7.
Cf. Phlb. 47c1–d6 and 50c10–e2.
As for the musical terminology, harmoniē is attested only seven times in the Hippocratic corpus (four in Vict. 1.8, VI.482 L. = 132,6–15 Joly-Byl), and symphonia (also mentioned in the speech of Eryximachus in Symp. 187b4–5: “harmony [harmonia] is consonance [symphonia], and consonance is a kind of agreement”) is attested only in On Regimen (Vict. 1.8, VI.482 L. = 132,6 and 9 Joly-Byl; and 1.18, VI.492 L. = 138,25 Joly-Byl). Cf. Marino 2016, 250.
Plato, Phd. 85e3–86c2.
Cf. Wöhrle (1990) 137.
Phlb. 64d9–e3, tr. Frede (modified).
Cf. Aristotle (Gen. corr. 2.3, 330b16–17) quoting from Plato’s Divisions: “The middle makes a mixture” (to gar meson magma poiei).
Part. an. 3.12, 673b26; Gen. an. 2.6, 744a30.
Gen. corr. 2.10, 336b20–21.
Another 50 or so occurrences of these terms are attested in spurious works, most remarkably in Problemata 14 (909a12–909b9) in the section entitled
Nonetheless, Carter complains that “Aristotle’s theory of mixture is not very precise” (2019), 129. Cf. Bogen 1996.
See Plato, Phlb. 47c3–d3 and 63e9–64a1; Ti. 74c5–d4.
Top. 4.2, 122b26–33. See also Top. 4.2, 123a4–5:
Aristotle is well aware of the novelty of his understanding of mixis. See Gen. corr. 1.6, 322b8–9: “Now, aggregation (synkrisis) is mixing (mixis); but what we mean by ‘mixing’ (mignysthai) is not yet clearly determined.”
Gen. corr. 1.1, 314b6–8. Cf. Vict. 1.4 (VI.476 L. = 128,6–7 Joly-Byl), tr. Jones: “Whenever I speak of becoming or perishing I am merely using popular expressions; what I really mean is mingling and separating (
Gen. corr. 2.6, 333b13–20. According to Empedocles, homoiomerous parts, such as bones (DK 31 B 96, cf. Aristotle Part. an. 1.1, 642a16–23), flesh (DK 31 A 78), and blood (DK 31 B 98), are made of the four elements in a particular ratio.
Gen. corr. 1.8, 325b20–24. Later in the text, Aristotle identifies a paradox as to “how flesh and bones and any of the other compounds will result from the elements” (Gen. corr. 2.7, 334a18–21), which is immanent in every doctrine in which elements do not come to be from each other, as is the case in the doctrine of Empedocles (Gen. corr. 2.7, 334a26–31).
Cf. Gen. corr. 1.2, 315a33–35; 1.8, 324b35–325a3; and 1.8, 325b13–16.
Gen. corr. 1.8, 325b18–20.
Cf. Williams (1982) 142.
Gen. corr. 1.10, 328a9–10.
Gen. corr. 1.10, 328a11–13, tr. Williams. See Joachim (1904), who suggests that Aristotle draws a distinction between a mechanical mixture (synthesis) and a “chemical combination” (mixis), which gives rise to homoiomerous bodies. Nevertheless, as Joachim admits, Aristotle occasionally uses the term mixis (and meignymi) in a less technical sense, for example when referring to the mechanical mixture of barley and wheat in Gen. corr. 328a2. This ambiguity of the term mixis, which in common language covers both “chemical combination” and mechanical mixtures, may explain Aristotle’s marked preference for the term krasis in his zoological works. I owe this suggestion to Claudia Mirrione.
Gen. corr. 1.10, 328b23.
Gen. corr. 1.10, 328b20–22.
Gen. corr. 1.10, 328b3–5, tr. Williams. Cf. Gen. corr. 2.2, 330a5–7.
It should be noted that the expression hygron has two different meanings: “Dry (xēron) and moist (hygron) are used in several senses; for both moist and damp (deiron) are opposed to dry, and again, solid (pepēgos) as well as dry is opposed to moist” (Gen. corr. 2.2, 330a13–15). Within the discussion of mixtures, the liquidity (as opposed to a solid state) is essential (cf. 327a18).
Top. 4.2, 122b26–33. Even solid substances, such as tin and copper (e.g. Gen. corr. 1.10, 328b7–9), can be blended if we melt them to form a liquid. See also Vict. 1.32 (VI.506 L. = 148,9–10 Joly-Byl).
Gen. corr. 1.10, 328a26–32, tr. Williams.
The significance of the specific accounts of elements and qualities in the Hippocratic On Regimen and On the Nature of Man for Aristotle’s theory of matter has been stressed by several scholars, including Vizgin (1980); Althoff (1992) 12–13, n. 8 and 9; Longrigg (1993) 220–226; Burnyeat (2004) 18–19 n. 24; Rashed (2005) XXV, n. 1, and XXVI; Lefebvre (2018) 286–300; and Mirrione (2021).
Aristotle describes in detail the origin of homogeneous materials in Mete. 4, in which the concept of proportion plays a fundamental role. Cf. Lennox (2014) and Popa (2020).
Gen. corr. 2.7, 334b20–31, tr. Williams.
Cf. Gen. corr. 1.10, 328b1–5.
As Aristotle remarks in Rhetoric (1.12, 1373a32–35), thieves in general often steal “objects that can easily be changed in shape, colour, or blend (
Gen. corr. 1.10, 328a9 (quoted above). There is also one occurrence of synkrasis in Gen. corr. 2.10, 336b20–21, tr. Williams: “Often, however, it happens that things perish in a shorter time on account of the mingling (synkrasis) of things with one another.”
As for the use of mixis, Aristotle occasionally employs it as a generic term for a blend in the physical sense, e.g., a mixture of wine and water (Gen. an. 2.8, 747b6–8) or of colours (e.g. Sens. 440a, 28–29; 442a12–13), while elsewhere he speaks of kraseis of colours (Rhet. 1.12, 1373a31) or drinks (Pol. 2.1, 1262b18). On several occasions in Politics, Aristotle speaks rather metaphorically also about a mixis of political constitutions, for instance politeia can be defined as a mixture (mixis) of oligarchy and democracy (Pol. 4.6, 1293b33–34, see also 1293b17–18 and 1294b13–14). In his biological works, Aristotle—as a rule—reserves the term mixis to cases of mixing male and female in sexual intercourse, reproduction and breeding (e.g. Gen. an. 1.2, 716b1–3; 2.7, 746b12–15 and 746b21–24; 2.8, 748b31–33; 4.2, 767a22–23; see also Hist. an. 7/8.28, 607a1–5).
Top. 6.2, 139b19–21 and 6.6, 145b7–11.
The authors of On Regimen (Vict. 1.32, VI.506 L. = 148,4 Joly-Byl; 3.81, VI.630 L. = 214,4 Joly-Byl; 3.82, VI.632 L. = 214,26 Joly-Byl; 4.89, VI.644 L. = 220,20 Joly-Byl) and On the Nature of Man (Nat. hom. 9, VI.52–54 L. = 188,15–17 Jouanna; and 22 [= Salubr. 7], VI.84 L. = 218,2–4 Jouanna) both speak about health and disease in terms of hexis of the body, i.e., the condition of a particular individual in a particular situation, that must be allowed for in dietetic treatment.
In Ph. 3.1 (201a34–b3), Aristotle suggests that the subject to the healthy or unhealthy condition may be “the moisture (hygrotēs) or blood”, while in Ph. 2.2, (194a23–24) he specifically considers it to be “bile and phlegm”. In Hist. an. 3.19 (520b19–31), the healthy condition of the blood is discussed in detail.
Ph. 7.3, 246b4–6, tr. Hardie and Gaye (modified).
Cf. Gen. corr. 2.1. See also Part. an. 2.2, 648b2–6.
Cf. Eth. Nic. 10.3, 1173a24–28.
Eth. Nic. 7.14, 1154b12–15. For medical aspects of Aristotle’s account of akrasia, see Francis (2011).
Gen. an. 5.2, 781a33–b2. Cf. the Hippocratic Carn. 15 (VIII.602–604 L. = 152.23–154.5 Potter, tr. Potter): “There are many proofs that what is driest echoes best … now nothing moist echoes, but rather what is dry, and it is what echoes that gives rise to hearing”.
C.f. Eth. Nic. 2.2, 1104a12–19; Pol. 7.16, 1335b6–8; Eth. Eud. 2.1, 1220a22–27, and 2.5, 1222a28–31.
See also Aristotle’s remarks on health in Ph. 4.3, 210a20–21 and 210b24–27; Cat. 7, 8b35–39a1; Gen. corr. 1.7, 324a15–19, and 324b1–4.
Cf. Bartoš (2021) 51–53.
Eth. Nic. 3.5, 1114a14–16.
Pol. 7.16, 1335a39–b12.
Cf. Pr. 14, 909a13–18: tr. Hett: “For the best mixture (aristē krasis) benefits the mind but excess disturbs it, and just as they cause distortion to the body, so do they also affect the mental temperament (tēs dianoias krasin).”
Cf. Gen. an. 4.10, 777b7–8, tr. Peck: “The reason why any animal is long-lived really is that its blend (
Hist. an. 7/8.28, 605b22–24.
For krasis as a climate zone, see Mete. 2.5, 362b12–20.
Hist. an. 7/8.28, 606a25–b6, tr. Balme.
Hist. an. 7/8.28, 606b17–20. Cf. Gen. an. 2.7, 746b7.
Cf. Aer. 12 (II.52–54 L. = Diller 54,10–17 Aer. 16 (II.62 L. = 62,1–6 Diller); and Aer. 23 (II.84 L. = 76,17–78,8 Diller).
Hist. an. 7/8.2, 589a11–18, tr. Balme.
Hist. an. 7/8.2, 589b23–26, tr. Balme.
Hist. an. 7/8.2, 590a13–19. Cf. Balme 1991, 80–81. See also Part. an. 3.6, 669a7–14, and Empedocles DK 31 A 72.
Gen. an. 4.2, 767a30–35. On the basis of this and several other passages from Gen. an., book 4 (e.g. 766a16–22; 766b12–16; 767a13–23; 767a23–28; 767b16–23; 768b27–33), van der Eijk (2007) argues that Aristotle’s account was inspired by On Regimen.
Gen. an. 4.10, 777b18–29.
Cf. Nat. hom. 3 (VI.38 L. = 170,11–172,2 Jouanna), Vict. 1.4 (VI.474 L. = 126,20–28 Joly-Byl) and 2.56 (VI.566 L. = 178,16–18 Joly-Byl), Aph. 5.62 (IV.556 L. = 174,18 Jones), Aer. 5 (II.22 L. = 32,12–13 Diller, and II.24 L. = 32,20–21 Diller), VM 14 (I.602 L. = 46,1–4 Heiberg) and 19 (I.618–620 L. = 50,28–51,4 Heiberg).
Aer. 5 (II.24 L. = 32,20–24 Diller).
Nat. hom. 3 (VI.38 L. = 170,11–172,2 Jouanna), tr. Jones (modified).
Hist. an. 3.19, 520b10–11.
Menstrual blood is the female semen and the prime matter (prōtē hylē) of animals (Gen. an. 1.20, 729a32–33), while male semen is a derivate of blood (cf. Gen. an. 2.3, 736b25–27).
Part. an. 2.4, 651a13–15.
Part. an. 2.2, 647b31–34. Cf. Part. an. 2.4, 651a14–17: “It therefore makes a great difference whether it is hot or cold, thin or thick, muddy or pure”.
Part. an. 2.3, 650a35–b2.
Part. an. 3.4, 666a36–b1.
Part. an. 3.12, 673b24–31, tr. Lennox (modified).
Part. an. 2.4, 651a12–15, tr. Lennox.
Part. an. 2.7, 652a28–29.
Part. an. 2.7, 652b20–22.
Part. an. 2.7, 652b26–27.
Part. an. 4.10, 686a5–11, tr. Lennox.
Aristotle situates the seat of perception into the heart (cf. Part. an. 2.10, 656a27–31, Sens. 2, 439a1–2, 7, 449a17, Somn. 2, 455b10; Insomn. 3, 461a6–7). Concerning the communication between the peripheral sense organs and the heart, it is unclear whether it is due to the connecting blood vessels, the blood in the blood vessels, or the pneuma in the blood (see Roreitner 2020).
Part. an. 2.7, 652b33–36.
Part. an. 2.2, 648a2–4.
Part. an. 2.2, 648a9–11. Cf. Aristotle’s explanation of the fact that bregma (i.e. the anterior fontanelle) is the last of the bones to be formed and still soft in the case of children in Gen. an. 2.6, 744a26–31: “The reason why this occurs especially in man is that in man the brain is more fluid and greater in volume than in any other animal, and the reason of this, in its turn, is that the heat in the heart is purest in man (
Part. an. 2.4, 650b27–33, tr. Lennox. For the connection between fear and cold, cf. Part. an. 3.4, 667a16–19, and 4.11, 692a22–25; Rh. 2.13, 1389b31–32.
De an. 1.1, 403a32–b1.
De an. 1.2, 405b5–8.
De an. 1.2, 405b1–5. Cf. Empedocles’ DK 31 B 105 attesting the opinion of common men that “the blood around the heart in human is thought”.
Morb. I, 30 (L 6.200).
Flat. 14 (VI.110 L. = Heiberg 99,20–100,3).
Vict. 1.35 (VI.518 L. = 154,21–156,3 Joly-Byl). Also, the circuit of the soul (e.g. Vict. IV.90, VI.654 L. = 226,14 Joly-Byl) can be related to the flow of blood, according to Hüffmeier (1961,) 76) and Jouanna (2012, 217).
De an. 1.4, 407b30–32.
De an. 1.4, 407b27–29. Cf. Pol. 8.5, 1340b10–19, tr. Jowett: “There seems to be in us a sort of affinity (syngeneia) to musical modes (harmoniais) and rhythms, which makes some philosophers say that the soul is a harmony, others, that it possesses harmony (harmonia)”. See also Plato’s Laws (10.889b–d) in which a similar doctrine is considered as one “which many people regard as the highest truth of all”.
Despite the fact that both philosophers speak about a widespread theory, the Hippocratic account in On Regimen (chap. I, 35–36) is the only extant pre-Platonic evidence for a theory identifying the soul and its conditions with krasis of the bodily constituents.
Similarities between Aristotle’s theory of the soul and the theory of harmonia/krasis mentioned in De an. I, 4 (407b27–32) have been noted by Hicks (1907, 263) and supported by Ross (1961, 195), Gottschalk (1971, 188), and M. Frede (1992). Polansky (2007, 103–104) suggests that the harmony theory “might be supposed very close to Aristotle’s own”, and most recently Carter (2019, 125) concludes that “it is not clear how this theory of soul differs from Aristotle’s”. See also Betegh (2021) and Bartoš (2015, 241–289).
De an. 1.4, 408a2–4: “It seems more in accord with the facts to connect harmony with health or generally with good condition (tōn sōmatikōn aretōn) of the body than with the soul.” Carter 2019, 123 acknowledges that “the harmony theory of soul was a live one for members of the Lyceum, since two of Aristotle’s students—the famed musical theorist Aristoxenus (fl. 335 BC), and the philosopher Dicaerchus (c. 350–285 BCE)—are reported by Cicero to have believed in it.”
De an. 1.4, 407b32–34.
De an. 1.4, 408a13–18. A direct attack against the theory of Empedocles follows this passage (408a18–24) in which Aristotle speaks consistently about mixis instead of krasis.
De an. 1.4, 408a9–12.
Metaph. 8.2, 1042b15–19, tr. Ross.
Metaph. 8.2, 1042b27–32, tr. Ross (modified).
Resp. 480b22–30.
Galen Temp. I.1 (I.509 K.), tr. Singer. On the specifics of Galen’s theory of mixtures, see van der Eijk (2015) and Mirrione (2017).
Galen Temp. II.4 (I.605 K.).
See also Temp. II.6 (I.628 K.), tr. Singer: “This distinction, too, was well made by Aristotle, who applied it in many cases.”); and Temp. III.4 (I.672 K., tr. Singer: “The solution lies in the distinction, given to us by Aristotle, between something cold in its own nature and something cold incidentally”).
I am grateful to the audiences in Prague, Athens, and Paris for their suggestions and criticism of earlier versions of this paper, especially to Philip van der Eijk, Jim Lennox, Gábor Betegh, Karel Thein, Tiberiu Popa, Claudia Mirrione, David Lefebvre, and Cristina Cerami.
Bibliography
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