The Visibility of the Aorta. Anatomical Ideas Behind an Ancient Etymology (Aristotle, Historia Animalium, 3, 513a)

1 Hook, Connection, Artery, or Aorta? The Fluid Semantics of ἀορτή as a Technical Appellation

Aristotle begins his well-known description of the network of blood vessels from the anatomical centre of the body, and more particularly from the heart, which he considers the origin of the network and the site of blood production. The passage reads as follows (T1):^[1]

Ἔχει δὲ τοῦτον τὸν τρόπον ἡ τῶν φλεβῶν φύσις. Δύο φλέβες εἰσὶν ἐν τῷ θώρακι κατὰ τὴν ῥάχιν ἐντός, ἔστι δὲ κειμένη αὐτῶν ἡ μὲν μείζων ἐν τοῖς ἔμπροσθεν, ἡ δ′ ἐλάττων ὄπισθεν ταύτης, καὶ ἡ μὲν μείζων ἐν τοῖς δεξιοῖς μᾶλλον, ἡ δ′ ἐλάττων ἐν τοῖς ἀριστεροῖς, ἣν καλοῦσί τινες ἀορτὴν ἐκ τοῦ τεθεᾶσθαι καὶ ἐν τοῖς τεθνεῶσι τὸ νευρῶδες αὐτῆς μόριον. Αὗται δ′ ἔχουσι τὰς ἀρχὰς ἀπὸ τῆς καρδίας· διὰ μὲν γὰρ τῶν ἄλλων σπλάγχνων, ᾗ τυγχάνουσι τείνουσαι, ὅλαι δι′ αὐτῶν διέρχονται σωζόμεναι καὶ οὖσαι φλέβες, ἡ δὲ καρδία ὥσπερ μόριον αὐτῶν ἐστι, καὶ μᾶλλον τῆς ἐμπροσθίας καὶ μείζονος, διὰ τὸ ἄνω μὲν καὶ κάτω τὰς φλέβας εἶναι ταύτας, ἐν μέσῳ δ′ αὐτῶν τὴν καρδίαν.

Actually, the natural scheme of the blood vessels is as follows: There are two blood-vessels in the thorax beside the backbone, on the inside, and the larger of the two is placed in front, and the smaller behind it. The larger is rather over to the right side of the body, and the smaller to the left, and this one some call the aorta because they have observed the sinewy part of it even in the bodies of dead animals. These blood vessels have their starting point in the heart, as is shown by the fact that whatever other viscera they happen to go through on their course, they pass through them intact, retaining their character of blood vessels; whereas the heart is, as it were, a part of them, and especially of the front (large) one, because these two blood vessels are above and below, while the heart lies in the middle between them.

Two main vessels are identified as connecting to the heart, one more on the right and in an anterior position, the other more on the left and in a more posterior position towards the backbone.^[2] But the most important information concerns the different size of the two main vessels: The first, the one located further on the right side in the (human) chest is also bigger (μείζων) than the one located on the left. In describing the comparatively greater size of this blood vessel, Aristotle implicitly alludes to the name that consistently identifies the vena cava in his biological writings, and which takes its name from its size: μεγάλη φλέψ.^[3] Whereas the rather transparent etymology for this blood vessel might make it unnecessary to repeat its name immediately after the mention of its greater size compared to the others, the same cannot be said for the aorta, whose etymology would have been much more opaque for an ancient Greek speaker and for which Aristotle takes care to report a possible etymological explanation.^[4] After all, it is worth noting that it was Aristotle who systematically adopted the term ἀορτή for the blood vessel that we call the aorta today.^[5] Already in ancient times, Rufus of Ephesus (1st c. CE) noted that Aristotle, in a distinctive and perhaps pioneering manner, was likely the first to canonize the use of the term ‘aorta’ to designate a specific artery, thereby setting himself apart from other specialists of his time.^[6]

Given this systematic use of a new term to designate a particular blood vessel, it is important to examine the attention that Aristotle pays to the etymological question of the term itself. Aristotle’s etymology provides a first explanation for his adoption of the term. As a matter of fact, the term ἀορτή is followed by a syntagma, ἐκ plus genitive, which refers to its etymological origin. It is very similar to other syntagmatic expressions of ancient Greek etymology such as παρὰ τό or ἀπὸ τοῦ, which normally introduce an etymological glossing of a term.^[7] Aristotle does not take responsibility for this statement but merely reports it as the viewpoint of others, according to whom the origin of the noun is due to the visibility of this blood vessel, particularly its sinewy part, during the dissection of animal corpses.^[8]

Remarkably, this rather explicit etymology based on the aorta’s visibility appears largely to have escaped the notice of commentators. On the contrary, other etymologies have been attributed to Aristotle, such as the one suggested by Scaliger in the 16th century. According to the Italian philologist (and physician), Aristotle derived the name of the aorta from its nerve component (quoniam nervosa), which consists of sinewy, tendon-like elements that make the blood vessel resemble a rigidly stretched rope raising up the heart (ἀείρω > ἀορτή) and hanging down from it (…contentione, qualis in nervis est, ut ait Aristoteles…).^[9]

Diverging from Scaliger’s hypothesis, medieval translators of Aristotle suggest that Aristotle’s adoption of the term ἀορτή is based on the visual prominence of this blood vessel for a human observer inspecting the dead body of an animal. In particular, William of Moerbecke’s mid-13th century translation of the Historia animalium, the first in the Western Middle Ages to be made directly from ancient Greek, renders ἐκ τοῦ τεθεᾶσθαι with the Latin subordinating particle eo quod: …minor autem in sinistris, quam quidam vocant aorten eo quod visa sit et in mortuis nervosa ipsius pars (‘…some call the smaller one, on the left, the aorta, because its sinewy part was observed in dead bodies as well’).^[10]

The text of the Arabic translation of the Historia animalium, which probably originated in the intellectual environment of Al-Kindī in the 9th century CE, also connects the name of the aorta with its particular observability during the anatomical examination of a dead animal:^[11]

wa-huwa al-ʿirq allaḏī sammāhu baʿḍu al-nāsbil-yūnāniyya awarṭī li-ʾannahum ʿāyanū al-juzʾa allaḏī fīhi min ʿaṣab fī al-ʾajsādi almayyita.

…and this is the vessel that some people have named in Greek awarṭī (اورطي) because they inspected with their very eyes the part in which there is some nerve in dead bodies.

More recently, scholars of historical linguistics have attempted to investigate the origins of the noun’s etymology and have suggested that the term could be an apophonic form of the root of the verb ἀείρω – meaning ‘to lift’, ‘to hang’ – which could explain the designation of the aorta as a structure that lifts and suspends the heart, or even the lungs if one takes it as designating the windpipe or the bronchi.^[12]

If the discussion about the etymology of the term ἀορτή goes back at least as far as Scaliger, the etymological reflection on this term must have been no less important at the time when Aristotle wrote his biological treatises. This is clear from the wording the philosopher uses to illustrate a debate about the choice of the name ἀορτή to designate a particular blood vessel. Aristotle does not present the etymology as unanimously accepted, instead attributing it to ‘some’ (τινες) without specifying whether they are physicians, philosophers, or specialists in other traditions of knowledge preceding him. It is possible that Aristotle had physicians in mind since in other passages of the biological treatises, expressions introduced by the indefinite pronoun τινες could refer to opinions and statements attributed to physicians;^[13] after all, Aristotle’s continuous dialogue with the traditions of medical knowledge that formed the so-called Corpus Hippocraticum is well known and remains a focus of critical interest.^[14] It is possible that the reference to τινες in the Historia animalium refers to certain physicians, although in the medical treatises that have reached us from the fifth and fourth centuries, the use of the term ἀορτή to designate a blood vessel appears only twice, in the de Corde, a treatise whose dating is debated but which can hardly be considered to predate Aristotle.^[15] In the two passages of the de Corde, ἀορτή actually refers to blood vessels stemming from the two main chambers of the heart, but there seems to be no precise distinction between the pulmonary artery from the right ventricle and the aorta from the left ventricle. Both are referred to as ἀορταί.

In the doxographical section immediately preceding T1, the only author to explicitly mention a vessel connected to the heart is, according to Aristotle, Diogenes of Apollonia.^[16] Whereas the physicians Syennesis and Polybus, the other two authors who give a description of the network of blood vessels in the human body, do not include the heart in their accounts, Diogenes speaks of it in connection with a pair of blood vessels branching off from the two main ones, the so called ἡπατῖτις and σπληνῖτις, which run vertically on either side of the spinal column. Diogenes describes these branches as the largest (μέγισται) going to the heart (εἰς τὴν καρδίαν), but there is no explicit mention of the aorta as such.^[17]

Correctness in the choice of words and precision in their use, whether to indicate specific anatomical parts or to describe physiological or pathological conditions of the human body, have been the focus of centuries of intellectual debates in the field of ancient medicine since the first evidence we have from the mid-5th century BCE with some of the Corpus Hippocraticum (CH) texts.^[18] The technical vocabulary of ancient Greek medicine developed through different phases of elaboration and different linguistic procedures, from the simple formation of neologisms to the attribution of new meanings to terms already present in common lexicon of ancient Greek speakers.^[19] Moreover, not all linguistic labels have maintained semantic stability: Over the centuries of intellectual discussions on anatomy, many words have changed meaning or have been given very different semantic values from those with which they were originally used. This phenomenon also has hermeneutic repercussions for modern scholars, who are faced with technical terms used today to discuss the tradition of medical knowledge that have not always had a unique and stable meaning; on the contrary, many have been the subject of complex dynamics of intellectual and cultural negotiation between physicians and philosophers in the ancient and medieval worlds.^[20]

The two terms ἀρτηρία and ἀορτή offer a good illustration of the problematics of ancient medical vocabulary. Whereas their use today is precise and restricted to the designation of specific key parts of the arterial vascular system, in older anatomical texts, including some Hippocratic treatises and works in the Aristotelian corpus, they are deployed differently. A few decades before the distinction between the venous and arterial systems emerged in Hellenistic medicine,^[21] the term ἀρτηρία designated a conduit not necessarily related to blood circulation,^[22] whose most common meaning (at least in Aristotle’s corpus) was the windpipe or trachea, the airway for the passage of air to and from the lungs.^[23]

There appears to be semantic fluidity, too, in instances where the same term, ἀορτή, is used to refer to certain anatomical components directly related to the trachea. Thus, in a treatise belonging to the CH, the de Locis in homine (which dates to the end of the 5th century BCE), this noun clearly designates the bronchi that branch off from the trachea into the lungs, connecting the former to the latter.^[24] The evidence of some texts from the Corpus Hippocraticum and Aristotle allows us to understand the extent of an ancient debate about the precise semantic value of the term ἀορτή in the medical field and its appropriateness for designating this or that anatomical part. The possibility of referring to both the trachea and the blood vessel of the aorta as ἀρτηρίη, and the confusion that could arise from this overlapping of two referents for the same linguistic sign, also seems to emerge from a particular expression found in book three of Aristotle’s Historia animalium in the section on blood vessels. In his description of the blood vessels that branch off from the vena cava and ascend to the skull, leading into the neck and encircling the trachea, Aristotle refers to the latter as the ἀρτηρίη of the lungs (τὴν ἀρτηρίαν…τὴν τοῦ πλεύμονος).^[25] This is a very unusual qualification of the windpipe, as Pierre Louis noted,^[26] but it can easily be explained by the fact that in this case Aristotle designated the trachea more clearly and unambiguously to avoid possible confusion with the aorta or any other blood vessel arising from the heart, which could also be referred to as ἀρτηρίη in medical texts and anatomical accounts. An obvious example of this usage can be found in the aforementioned de Corde, in which the blood vessel of the pulmonary artery, which originates from the right ventricle of the heart, is referred to as ἀρτηρίη.^[27]

Evidence from Hippocratic treatises and the reference to the etymology of ἀορτή in Aristotle’s text (T1) indicate a fluidity of semantic usages that is typical of a specialised vocabulary under construction. Such a debate about appropriate nomenclature certainly also included etymological discussions in which an attempt was made to link a particular material feature of this or that anatomical part with a specific etymology, in a sense reflecting a precise anatomical image or conformation. The etymological debate continues today when it comes to finding an explanation for the specific use of the term ἀορτή to designate a particular blood vessel.^[28]

In this paper I intend to show that the reconstructive etymological hypotheses offered by modern historical linguistics can be critically juxtaposed with the etymological reflections articulated by cultural insiders, notably ancient Greek-speaking authors. These insights yield alternative representations and divergent conceptualizations akin to folk^[29] etymologies originating from within the culture under examination. In light of this, my paper aims to illustrate that such etymological narratives hold significant potential for elucidating ancient medical conceptions of human anatomy. This article attempts to show how linguistic-terminological discussions condense broader debates about the functions and nature of this or that anatomical part. All of this offers scholars valuable insights into the rationale behind the attribution of specific onomastic labels, thus enriching their comprehension of the cultural and intellectual milieu of the era.

2 Etymology as a Heuristic Tool in the Aristotelian Biological Corpus

Aristotle’s contributions to the study of language, particularly the relationships between words, conceptual representations, and sensations, were pivotal in shaping the ancient debate on linguistic theories.^[30] Adopting a largely conventionalist approach to human language, Aristotle rejects the indiscriminate multiplication of arbitrarily chosen names that lack a connection to the conceptual representation of the designated entity. When it becomes necessary to introduce a new word or reinterpret an existing term, Aristotle emphasises the importance of linguistic familiarity and appropriateness.^[31] He insists that new terms must be closely related to established semantic constructions, phrases, and linguistic usages that are already prevalent and deeply embedded within the linguistic community.^[32]

It is no coincidence that in highly specific areas of inquiry, such as the study of living organisms, Aristotle, when confronted with the absence of established terms to describe the similarities and differences between animals, physiological functions, or anatomical parts, often notes that no such terms exist. He frequently chooses not to create new names in these situations, instead indicating them through periphrastic and descriptively anonymous formulations.^[33]

In other cases, however, Aristotle appears to appropriate linguistic labels rooted in everyday vernacular to denote specific parts of the living body. It is important to recognise that certain external and internal body parts already had specific names due to their frequent association with culturally significant social practices, such as ritual sacrifice.^[34] Some of the viscera of the sacrificial animal, for example, already possessed established names within the cultural lexicon of antiquity.

Aristotle’s etymological reflections on certain anatomical features of the neck region seem to exemplify this phenomenon. His description of the neck includes two tubular structures, passageways that join the oro-pharyngeal cavity to the internal organs of the body: One is the trachea, reaching the lungs, and the other is the oesophagus. If the trachea is simply called ἀρτηρία, as is always the case in Aristotelian biological treatises, the term for the oesophagus is different, and the author introduces an etymological clarification. This organ is presented as having two different names: One of them, οἰσοφάγος, has been used continuously in the medical tradition up to modern times; the other, στόμαχος, was reappropriated to designate another part of the digestive system.^[35] In the passage on the oesophagus, Aristotle employs two different linguistic strategies for presenting the two names of the part. Whereas the first term is explicitly expressed by the word οἰσοφάγος and preceded by the middle participle of the verb καλεῖν, καλούμενος (namely ‘the so-called’), the second appellation of the same part is only implicitly evoked by means of an etymological reanalysis, and it is not explicitly mentioned in the text. Aristotle accordingly reports that the oesophagus also takes its name from the length (μῆκος) and narrowness (στενότης) of the channel going to the stomach from the pharyngeal cavity.

In this context, Aristotle attributes the name οἰσοφάγος to others, but he does not seem to explain the linguistic reasons that would have led other physicians or naturalists to give this name to the channel leading from the pharynx to the stomach.^[36] Such a name for the oesophagus was certainly rarer and was most likely a technical term to distinguish this channel from other tubular ducts in the bodies of living beings. But in his biological treatises Aristotle most often chooses to use the other term, στόμαχος, which was far more widespread and already attested in the Homeric epics, where it designated the throat.^[37] It is possible that Aristotle’s evocation of the term’s etymology was to help justify using this seemingly less appropriate term in a treatise on comparative anatomy by highlighting those characteristics of shape, narrowness, and length that were inscribed in the very name of this anatomical part. It is important to note how the different etymological analyses of the same names are closely linked to debates about the forms and functions of specific anatomical parts. In this case, Aristotle reminds us on at least one occasion that the oesophagus is not a necessary part of the anatomy of living beings; there are some forms of life that do not require a passageway between the mouth and the stomach. But the presence of the oesophagus is conditioned by the presence of another essential anatomical part in breathing animals, namely the trachea, which must ensure the passage of air to the lungs. Aristotle reminds us that since the trachea always has a certain extension (ἐξ ἀνάγχης ἔχοντος μῆκος), the oesophagus must necessarily have a similar length as well in order to bridge the gap between mouth and stomach.^[38] The question of length and expansion thus turns out to be essential for defining the function and form of the oesophagus in Aristotelian anatomical discourse. Perhaps the etymological reanalysis offered by Aristotle should be understood from this point of view, and it is likely to challenge other etymologies that have been suggested, for example deriving στόμαχος from στόμα (mouth, opening).^[39]

However, this is not an isolated case in Aristotle’s biological corpus; on the contrary, etymological reflections are interwoven at various points in Aristotelian treatises with specific considerations relating to the anatomy of animals, including humans. This is the case in the de Partibus animalium when it comes to the discussion of a particular anatomical structure of the human body. Aristotle focuses on etymological reanalysis to highlight the uniqueness of the human face compared to other mammals by making use of etymology as a tool for argumentative persuasion. Drawing the contours of human uniqueness regarding bipedalism, Aristotle recalls how the part of the body located between the head and the neck is designated as πρόσωπον only in human beings because only humans look from a frontal position (πρόσωθεν ὄπωπε) and emit sounds to the front (εἰς τὸ πρόσω).^[40]

In his presentation of the peculiarities that characterise the anatomy of the animal head, Aristotle distinguishes human beings as the only ones who can perform certain physiological functions related to sight and vocal production in a very special way by virtue of the structural features of bipedality. In this case the etymological reflection is central to Aristotle’s anatomical discourse, and it demonstrates the validity of using the name πρόσωπον exclusively for humans by justifying it through the function (πρᾶξις) that this part of the body enables, characterising humans as unique in the world of animals. In a certain way, the name functions as a clear sign of the particular anatomical arrangement of the human being in relation to other animals. Anatomical information that accounts for the rightness of the designation of that peculiar anatomical part as πρόσωπον is condensed into the name itself. By using the expression ὡς εἰκός, Aristotle suggests that conferring this particular name on the basis of actions made possible by the human face is an act of coining a new name based on the reality of human anatomy.^[41]

Aristotle’s linguistic considerations highlight the relevance of etymological reasoning in ancient medical and technical writings, especially when discussing common names in connection with their somewhat specialised use for designating a particular part of the living body. Etymologies are not idle arcane constructions; quite on the contrary, they are important heuristic tools capable of providing those who know how to interpret them with important information condensed in the sequence of letters that make up the term.

This particular attention to linguistic and etymological issues in the process of developing names that uniquely identify particular anatomical parts is perhaps at least partly related to the zoological context of Aristotle’s work. The act of nomination is one of the most important practices in the zoological discourse. Information about the shape, colour, or other characteristics of a certain animal can prove essential when it comes to identifying them precisely on the basis of their names. A clear example of this mechanism can be found in the so-called ethological section of the Historia animalium. A particularly clear instance is in book VIII, in the section devoted to the ethology of some birds, including the greenfinch, to which Aristotle gives the vernacular name χλωρίς, derived from the characteristic yellow-green colour (ὠχρά) of the lower part of the body of this small bird.^[42] First, Aristotle provides the vernacular name normally given to the bird, then he presents the semantic explanation of the name by resorting to a para-synonymic term that can describe the chromatic characteristic from which the name is derived.

3 The Aorta and the Question of Visibility

In light of the preceding examples, which concern only a few passages from the biological treatises, it may be easier for us to grasp the importance that Aristotle assigned to the discussion about the exact meaning of the term ‘aorta’. What was at stake in such discussions was not just a matter of onomastics but rather which particular etymological explanation could be considered more accurate and reflective of the observed anatomical reality.

The etymological connection that some (perhaps physicians) before Aristotle had reconstructed between the name given to the aorta, that is, ἀορτή, and the idea of the particular visual salience of this blood vessel in animal cadavers can be seen more clearly by examining some of the information that Aristotle provides in his biological treatises. This could be an echo of ongoing discussions among ancient specialists regarding the particular nature of blood vessels. As a matter of fact, there are some Aristotelian passages that make visibility or invisibility a key criterion for distinguishing the vena cava from the aorta, in a framework lacking a clear functional distinction between arteries and veins. In a passage from the third book of the treatise de Partibus animalium, in which the heart is discussed as the sole source of blood and the principal organ of sensation, the two main blood vessels are also described as having their origin in the heart (T2):^[43]

Διὰ μὲν οὖν τὸ ἐν ἑνὶ εἶναι μορίῳ τὴν αἰσθητικὴν ἀρχὴν καὶ τὴν τῆς θερμότητος καὶ ἡ τοῦ αἵματος ἀπὸ μιᾶς ἐστιν ἀρχῆς, διὰ δὲ τὴν τοῦ αἵματος ἑνότητα καὶ ἡ τῶν φλεβῶν ἀπὸ μιᾶς. Δύο δ′ εἰσὶ διὰ τὸ τὰ σώματα εἶναι διμερῆ τῶν ἐναίμων καὶ πορευτικῶν· ἐν πᾶσι γὰρ τούτοις διώρισται τὸ ἔμπροσθεν καὶ τὸ ὄπισθεν καὶ τὸ δεξιὸν καὶ τὸ ἀριστερὸν καὶ τὰ ἄνω καὶ τὸ κάτω. Ὅσῳ δὲ τιμιώτερον καὶ ἡγεμονικώτερον τὸ ἔμπροσθεν τοῦ ὄπισθεν, τοσούτῳ καὶ ἡ μεγάλη φλὲψ τῆς ἀορτῆς. Ἡ μὲν γὰρ ἐν τοῖς ἔμπροσθεν, ἡ δ′ ἐν τοῖς ὄπισθεν κεῖται, καὶ τὴν μὲν ἅπαντ′ ἔχει τὰ ἔναιμα φανερῶς, τὴν δ′ ἔνια μὲν ἀμυδρῶς ἔνια δ′ ἀφανῶς.

Thus, we see that because the source of sensation and the source of heat are in one and the same part, the blood must originate from one source too; and because there is this one origin of the blood, the blood-vessels also must originate from one source. The blood-vessels are, however, two in number, because the bodies of the blooded creatures that move about are bilateral: we can distinguish in all of them front and back, right and left, upper and lower. And just as the fore part is more honourable and more suited to rule than the back part, so is the great vessel pre-eminent over the aorta. The great vessel lies in front, while the aorta is at the back. All blooded creatures have a great vessel, plainly visible; but in some of them the aorta is indistinct and in others it cannot be detected.

Information provided by this passage, along with that already encountered in the earlier section of the Historia animalium (T1), offers additional insights into the anatomical region Aristotle describes in his account of the μεγάλη φλέψ and the ἀορτή. Two distinguishing features that Aristotle mentions in relation to these major blood vessels are more clearly understood when examined in the context of the superior or cranial section of the animal’s body. Specifically, the μεγάλη φλέψ is described as being not only larger in diameter (T1) than the ἀορτή but also as being situated more to the right side of the body, while the ἀορτή is described as positioned further to the left and more posteriorly, near the spine (T1, T2). Assuming it is plausible that Aristotle based his description of the human vascular network on comparisons derived from dissections of mammals familiar to him (such as dogs, pigs, and oxen),^[44] we can observe that this anatomical portrayal corresponds roughly to the thoracic region in humans rather than the abdominal region.^[45] In the abdomen, the diameters of the μεγάλη φλέψ and the ἀορτή are nearly equal, and both vessels are centrally positioned rather than distributed along the left and right sides of the body.^[46]

In the passage under consideration, Aristotle introduces a distinction between the visibility of the μεγάλη φλέψ (the vena cava) in all sanguine animals and the poor visibility or invisibility of the aorta, depending on the type of animal being considered. As pointed out by James G. Lennox in his commentary on the passage, these observations can be explained by the fact that just after the killing of the animal, during the dissection, the aorta and the arteries would lose all the blood in them, while the veins would retain some of it due to the valves with which they are endowed.^[47] The discourse around blood vessels and the most important of them, the vena cava and aorta, very often hinges on the practice of dissection and the variables that can characterize autoptic anatomic inspection in the description of structures. As evidence of this, consider the section on blood vessels and the anatomy of the heart in the third book of the Historia animalium, in which Aristotle recalls how the conformation of the body of certain animals – for example, their structure, the presence of fat, or the extreme smallness of their bodies – sometimes makes it very difficult if not impossible to see, recognize, and describe the blood vessels, except for the vena cava which is always visible (διάδηλος), even in the smallest of the blooded animals.^[48] Aristotle makes the visibility of blood vessels a central point for the accuracy of knowledge about anatomy and the consequent accuracy of reconstructions of the functions and structure of the human heart. When in the third book of the Historia animalium he reproduces some of the most common ideas of some early physicians about the anatomy of the heart and the physiology of blood distribution, he attributes their lack of knowledge (ἄγνοια) to the structural difficulty of inspecting the blood vessels clearly and precisely, what he calls τὸ δυσθεώρητον.^[49]

According to Aristotle the structure and configuration of the layout of the blood vessels in an animal, their φύσις, may not be observable during a dissection due to the sudden leakage of blood from the vessels causing their structural collapse (τὸ συμπίπτειν).^[50] In the specific case of the ἀορτή and the blood vessels branching off from it, the question of their visibility is even more crucial because Aristotle points out that the vessels branching off from the aorta are smaller and much narrower compared to the network of blood vessels formed by the μεγάλη φλέψ and its branches. Whereas the aorta has a certain capacity in its first part, which is given by a uniform diameter, it and its branches become very narrow (ἐπιστενοτέρα) as they lead away from the heart, and they consist almost exclusively of sinewy and tendinous material (νευρωδεστέρα).^[51] Aristotle also uses the adjective νευρώδης in passages dealing with other anatomical structures, such as the muscle structure in the calf area, which has certain material properties that make such parts comparable to structures from νεῦρα. These properties certainly include the hardness, the tightness of the tissue, and its fibrous nature.^[52]

By comparing the aorta to the vena cava from a material point of view and on a macroscopic level, one may hypothesise that Aristotle, or those who had emphasized the aorta’s νευρώδης component, was looking at and referring to the nature of the tunica media of the aorta, which is much stiffer and thicker than the corresponding part that constitutes the middle layer of the vena cava.^[53] The tunica media is the middle layer of the vessel, made up of elastic and muscular tissue, and it regulates the internal diameter of the vessel. This would explain the possibility of associating the visibility of the aorta in dissected animals with the tendinous tissues and elastic fibres that confer a certain stiffness and greater consistency to the blood vessel of the thoracic and abdominal aorta, making it visible even after the blood has been drained following the killing of the animal.^[54] In a chapter of the third book devoted entirely to the νεῦρα, in the section on the uniform internal parts of the living body, immediately after the discussion of the vascular network, Aristotle makes the tendinous and sinewy nature of the aorta and its branches even clearer. Without pointing out that this is a condition due to the changes that occur during or after the dissection of an animal cadaver, and thus describing a condition that he probably considered normal and not pathological, Aristotle states that the terminal parts of the vascular network emanating from the aorta, the vessels in the most peripheral position (τὰ τελευταῖα), consist entirely of sinewy tissue. These parts of the network of blood vessels are so νευρώδη that in the composition of their tissue, especially their elasticity, and in the fact that they are full of matter and have no cavity for the passage of blood, they completely take on the nature of the νεῦρα, being ἄκοιλα, without cavities inside them.^[55]

4 The ‘Quite Visible’ Vessel. The ἀορτή and an Ancient Interpretation of Its Etymology

If one considers the exact wording of Aristotle, who explicitly attributes etymology of the name ἀορτή to the possibility that it can be seen when dissecting dead animals (ἐκ τοῦ τεθεᾶσθαι), it is possible to hypothesise that the name ἀορτή was conceived by some anatomists or physicians, the τινες mentioned by Aristotle, as deriving from the verb ὁρᾶν (‘to see’) with the addition of alpha intensivum as a compositional prefix.^[56] As a matter of fact, when it comes to the central part of ἀορτή as a compound name, it is worth considering that the linguistic form ἀορτή presents many structural and prosodic analogies with the verbal adjective derived from the verb ὁρᾶν, that is ὁρατός, -ή, -όν, which is widely used in Attic prose of the classical age.^[57] Verbal adjectives composed by means of the suffix -to/ā also present in their semantic spectrum the idea of condition and possibility, similar to adjectives formed with the suffix -able in English.^[58] If this hypothesis is correct, it would make it possible to account for the use of the verb θεάομαι in the perfect tense in connection with the etymology given for the term ἀορτή, a connection that has so far found no explanation in the secondary literature about this passage. The noun ἀορτή can be understood as an onomastic sign that, at least in the intentions of its creators, embodies a very specific anatomical idea consisting in the particular visual conspicuousness (ἀ-ορ(α)τή) of this blood channel due to the structural characteristics of its fibrous and sinewy component.

This hypothesis stems from an elliptical suggestion provided by the Aristotelian text, and as such it is grounded in the etymological knowledge and techniques prevalent in the ancient world. The hypothesis is situated within the ethno-linguistic framework of ancient Greek etymology and is not intended to challenge modern historical-linguistic explanations of the term ἀορτή. The principles governing etymologies in the ancient Greek context differ significantly from those in modern historical linguistics. For instance, while the derivation of ἀορτή from ὁρατή can be evaluated as implausible from a contemporary historical-linguistic standpoint – since the thematic vowel of the verb (ὁρα-) is typically retained in the formation of verbal adjectives – a different logic applies in the case of ancient etymology.

In tracing the linguistic relationship between terms, ancient grammarians and intellectuals – at least as far as we can reconstruct from Alexandrian etymological practice – frequently employed the principle of letter omission (also called παράλειψις by Aristarchus) to account for the apparent dissimilarity between two words. This approach was particularly applied in cases where vowel signs present in the original word were absent in the derived form. This method allowed for the explanation of discrepancies between related terms, illustrating the flexibility of ancient etymological reasoning in accommodating linguistic variations.^[59]

An example of this practice of etymological derivation can also be found in Aristotle’s explanation of the term ὀσφύς, which he uses to refer to the iliac bones that form the pelvis in the retro-lateral region of the human body. In his Historia animalium he explicitly connects the term ὀσφύς to the bilateral symmetry (ἰσοφυής) of the two pelvic bones, which together create a balanced structure on both the right and left sides. This symmetrical formation, according to Aristotle, provides both the name and the etymological basis for the Greek term for the pelvis, i.e., ἰσοφυές > (ἰ)ὀσφύ(ε)ς (scil. διάζωμα, i.e., ‘partition’).^[60]

The passage from de Partibus animalium I mentioned above (T2) may seem to challenge the interpretation of the etymology reported by Aristotle. In this text, Aristotle recounts the prominence of the μεγάλη φλέψ, which is conspicuously visible in all animals, juxtaposed with the ἀορτή, scarcely discernible in certain animals and entirely imperceptible in others. Such observations suggest a potential contradiction between this passage from de Partibus animalium and the depiction of the aorta’s visibility in the Historia animalium (T1). Consequently, one might challenge the etymological reconstruction hypothesis by positing that the term ἀορτή could be analysed as a compound characterized by alpha privativum, thereby suggesting the designation of an ‘invisible’ (ἀ-ορατή) blood vessel.

However, several considerations render this objection unpersuasive. Foremost among them is the context in which the information regarding the aorta is presented. While the passage in the Historia animalium detailing blood vessels and cardiac anatomy is explicitly confined to human anatomy, including the preceding doxographic section with allusions to physicians of the Hippocratic tradition, the same cannot be said for the mention of the aorta in the de Partibus animalium. In this passage, and more generally in this treatise, Aristotle aims to elucidate the functions of distinct anatomical structures by reconstructing their operations through a comparative analysis of various animal anatomies, including but not limited to human anatomy. While within the Aristotelian formulation presented in de Partibus animalium, it is asserted that the μεγάλη φλέψ is universally and easily observable across all animals, there is also an acknowledgment of the challenge in observing the ἀορτή in certain species and of its complete invisibility in others. However, the repetition of the pronoun ἔνια (‘some, a number of’) does not exhaust the range of possibilities; Aristotle draws a distinction between a universal condition of the μεγάλη φλέψ applicable to all animals and the variable condition of the ἀορτή, which lacks consistency across different species.^[61] Had Aristotle intended to present a comprehensive depiction of scenarios regarding the visibility of the ἀορτή, he might have employed a disjunctive oppositional formulation utilizing particles such as ἤ…ἤ.^[62]

Hence, it is possible to reconcile the apparent contradiction between the two examined texts by positing that the passage in the Historia animalium pertains specifically to human anatomy, whereas the references in de Partibus animalium encapsulate a broader scope, encompassing the anatomy of non-human animals. Given the inherent challenges associated with the examination of smaller animal species, particularly in discerning anatomical features such as the aorta, a disparity in observational clarity emerges.

Furthermore, it appears unlikely that Aristotle would outright dismiss the term ἀορτή and its etymology concerning the visibility of the blood vessel within the context of anatomical dissection. The terminology employed in Historia animalium (T1) likely denotes a specialised linguistic convention introduced by others, which Aristotle deems acceptable due to its established usage and its unequivocal designation of the blood vessel originating from the central cavity of the heart in larger mammals. Had Aristotle harboured substantial reservations regarding this terminology, it is plausible that he might have proposed an alternative term, as evidenced in his biological treatises.^[63] In other cases, Aristotle typically exhibits a preference for retaining established terminologies coined by other experts such as physicians, particularly concerning human anatomy.^[64] It seems unlikely that Aristotle considered the etymology that linked the name ἀορτή to the particular perceptibility of this blood channel in the corpse of a dissected animal to be completely wrong (and therefore not to be adopted). When Aristotle expresses a strong criticism of the opinions of others, he uses explicit formulations (e.g., οὐ καλῶς λέγουσι) that do not occur in the text we are analysing.^[65] In another passage from Historia animalium, there is a formulation that is identical to the passage under discussion in T1, which considers the appropriate name for the mantle of cephalopods. Aristotle reports on the use of language by some unspecified people who refer to the mantle of the cuttlefish as a head (καὶ καλοῦσιν αὐτὸ κεφαλήν τινες), and adds immediately afterwards that this term is incorrect and should therefore not be adopted (οὐκ ὀρθῶς καλοῦντες).^[66]

This consideration is all the more significant when one recalls that it is Aristotle himself who is remembered in ancient doxography on anatomical terminology as the one who, if not introduced, then at least canonized the use of the term ἀορτή for the blood channel that emanates directly from the heart.^[67] As Galen states in his work devoted exclusively to angiology, others (ἄλλοι), and not Aristotle, called this blood channel the ‘great artery’ (μεγάλη ἀρτηρία).^[68] On this basis it would be problematic to believe that Aristotle adopted and stabilised the use of a term whose etymological justification he would consider deeply flawed and which was probably developed by the same specialists who first introduced the term.

In ancient exegetical speculation on the origin and meaning of words, especially in the tradition of commentary and exegetical studies of Homeric texts, the alpha intensivum is one of the grammatical tools developed by Greek scholarship of the classical and Hellenistic periods.^[69] Alongside the better-known alpha privativum, which semantically indicates the withdrawal or negation of the quality expressed by a particular adjective, the alpha intensivum was already analysed by Aristarchus of Samothrace (2nd c. BCE), an Alexandrine philologist and pupil of Aristophanes of Byzantium, as a form of semantic intensification and as an instrument for deciphering the meaning of certain particularly obscure or controversial words. On some occasions, Aristarchus explains some Homeric terms or criticises the explanations of others by resorting to the semantic value of alpha κατ′ἐπίτασιν (‘intensive’), as in the case of the epithet ‘noisy’ associated with the Trojans defined by Homer as ἄβρομοι, namely ‘those who make a lot (ἄγαν) of noise (<ἀ + βρέμω)’.^[70] The presence of alpha intensivum is not limited to grammatical speculation and analysis of ancient texts from the Greek poetic tradition, as it also seems to retain a certain lexical productivity if, for example, one considers certain passages from the Orphic Lithica dating back to late antiquity (4th c. CE), in which one can find nouns that are conceived through alpha intensivum to obtain new semantic effects. This is the case with ἄψυχος (l. 362), not to be understood as ‘dead’ but as ‘very much alive’, or with ἀμήχανος (l. 763), to be interpreted as ‘very much possible’ and not as ‘impossible’.^[71] A meta-linguistic reflection on the semantic values of the prefix alpha is already present in Aristotle’s time, as the etymological considerations of Socrates’ character in the etymological section on the names of Apollo in Plato’s Cratylus prove.^[72] In the last of the four etymological reanalyses of the meaning of Apollo’s name, Socrates defines the semantic core of the god’s appellation as closely linked to the idea of cosmic and musical harmony, guaranteed by the power of the god who is able to unite the stars of the heavens in their rotation. Socrates recalls that in ancient Greek, alpha could have the same semantic value as the adverbial prefix ὁμοῦ (‘together, with, at the same time’).^[73]

Parsing the noun ἀορτή as incorporating an initial alpha with the intensifying value (alpha intensivum) is thus not only plausible for Aristotle’s contemporary readership but emerges as a legitimate inference, particularly given Aristotle’s formulation of the passage in question. In recounting the etymological hypotheses of certain physicians or philosophers, Aristotle notes how this etymology of the term ἀορτή is grounded in the fact that even in the corpses of dissected animals the structure of the blood vessel remains visible (…καὶ ἐν τοῖς τεθνεῶσι…).^[74] The use of the participial noun τεθνεώς situates this passage within the context of dissection or the observation of deceased animals, distinctly separate from vivisection practices. Particularly noteworthy here is the blood vessel’s consistent and clear visibility in animal corpses, despite blood loss that ordinarily leads to the vessel’s collapse and disappearance, rendering it difficult – if not impossible – to observe, as Aristotle states in multiple passages cited above.^[75]

5 The ‘Great’ and the ‘Quite Visible’ (Vessels). A New Insight into Aristotle’s Syntax

The ancient etymological reconstruction I propose, which highlights the possibility that the term ἀορτή was originally analysed as a verbal adjective related to the verb ὁρᾶν, furthermore allows a somewhat different and more complete understanding of some expressions found in Aristotle’s biological writings concerning the major vessels.

The fact that the term ἀορτή was the subject of linguistic negotiation over its specialised and technical use to designate one of the two major blood vessels of the human body, becomes clearer by looking at the syntax of the Aristotelian text, specifically at the way in which the anatomical datum is presented linguistically and rhetorically. Although many pieces of the puzzle are missing and many aspects of the process of semantic stabilisation of the term remain unclear, one can see how in some Aristotelian passages the morpho-grammatical identity of the term was not fully defined, and semantic shifts from adjective to term in the syntactic placement of the term were still possible.

A particularly significant passage illustrating this phenomenon is the summary of the nature of the heart and the main blood vessels in the third book of the treatise de Partibus animalium (T3):^[76]

Δεῖ γὰρ εἶναι τόπον τινὰ τῆς καρδίας καὶ ὑποδοχὴν τοῦ πρώτου αἵματος. Ὅτι δὲ πρῶτον ἐν τῇ καρδίᾳ γίνεται τὸ αἷμα, πολλάκις εἰρήκαμεν, διὰ τὸ τὰς ἀρχηγοὺς φλέβας δύο εἶναι, τήν τε μεγάλην καλουμένην καὶ τὴν ἀορτήν. Ἑκατέρας γὰρ οὔσης ἀρχῆς τῶν φλεβῶν, καὶ διαφορὰς ἐχουσῶν, περὶ ὧν ὕστερον ἐροῦμεν, βέλτιον καὶ τὰς ἀρχὰς αὐτῶν κεχωρίσθαι·

There must be some place in the heart which will be a receptacle for the blood when first formed. As we have stated several times, blood is first formed in the heart. Now there are two chief blood-vessels, the so-called Great Blood-vessel, and the Aorta; each of these is the source of other blood-vessels; and the two differ from each other (this will be discussed later); hence it is better for them to have separate sources.

In attempting to explain the phrase διὰ τὸ τὰς ἀρχηγοὺς φλέβας δύο εἶναι, τήν τε μεγάλην καλουμένην καὶ τὴν ἀορτήν, it is certainly legitimate to follow the path taken by A. L. Peck in the above translation for the Loeb collection. Peck considers that the association with the participle καλουμένην applies only to the vena cava, which, as we have seen, is called the ‘great vessel’ in the ancient medical lexicon. While the term ἀορτή is presented as a noun in the full sense of the word, in the case of the vena cava Aristotle hints at the use of the expression μεγάλη φλέψ as a terminus technicus by making the participle καλουμένην following the adjective μεγάλην. According to this reading of the text, there is, on the one hand, a term fully defined in its nature as a noun referring to the aorta, namely ἀορτή, and, on the other hand, a syntagmatic construction with an adjective that qualifies and defines a particular blood vessel as ‘great’ (μεγάλη) in relation to the rest of the vascular network. The participle of the verb καλέω would be a technical language marker that refers exclusively to the term for the vena cava.

But the presentation of technical terms not yet established in the specialised language of ancient medicine also concerns the aorta in certain passages of Aristotle’s biological treatises. An exemplary case in this respect is the reference to the two large blood vessels and their branches in Aristotle’s account of the vascularisation of the brain with regard to the presence of heat in this anatomical region. Aristotle claims that the cranial area is surrounded by the branches of both blood vessels, the great one and the one called ἀορτή (ἀφ′ ἑκατέρας τῆς φλεβός, τῆς τε μεγάλης καὶ τῆς καλουμένης ἀορτῆς).^[77]

This example, considered alongside our previous considerations on the etymology of the term ἀορτή as attested by Aristotle, allows us to read the above passage (T3) differently by formulating the hypothesis that ἀορτή can also be understood as a verbal adjective that, like μεγάλη, would qualify the accusative plural φλέβας. In the specific case of this passage, Aristotle thus describes the two blood vessels as the large one on one side and the clearly visible one on the other.

Our hypothesis is likely to be strengthened by a similar formulation found in a passage from the treatise de Generatione animalium. In the first part of a paragraph dealing with female secretions, Aristotle mentions that the region of the uterus is abundantly supplied with blood by a network of blood vessels from the various branches of the two main vessels that descend from the region of the heart to the abdomen: Τοῖς μὲν οὖν θήλεσι περὶ τὸν τῶν ὑστερῶν τόπον, σχιζομένων ἄνωθεν τῶν δύο φλεβῶν, τῆς τε μεγάλης καὶ τῆς ἀορτῆς, πολλαὶ καὶ λεπταὶ φλέβες τελευτῶσιν εἰς τὰς ὑστέρας (…). ‘When it comes to the region of the uterus in females, many fine blood-vessels terminate in the uterus since the two blood-vessels, the great one and the ἀορτή one, divide from above (…)’ (transl. in Peck 1942, 181–182, modified).^[78] As can be seen from the syntax of the passage, the indication of the two specific blood vessels (i.e., the vena cava and the aorta) in the genitive (τῆς τε μεγάλης καὶ τῆς ἀορτῆς) is constructed as an apposition to the absolute genitive (σχιζομένων… τῶν δύο φλεβῶν), which expresses the concept of the subdivision of the two large vessels into several small vessels. In this passage, both μεγάλη and ἀορτή are constructed as attributive adjectives of the noun φλέψ, with both terms denoting the two major φλέβες, the great and the ἀορτή. In the light of the analyses offered in this article, it can be argued that in this case more than elsewhere it is possible to capture the semantic tension between the adjective and the noun forms of the term under study. Here, the word ἀορτή could explicitly refer to the aorta as the highly visible (ἀ-ορ(α)τή) vessel.

6 Concluding Remarks

By analysing the context of the anatomical depiction of the heart and the network of blood vessels that Aristotle provides in the first part of the third book of his Historia animalium, we were able to formulate a first plausible hypothesis about the ancient etymology of the term ἀορτή as Aristotle himself presents it. In the Aristotelian passage, the etymology of the noun is described as dependent on the visual prominence (ἐκ τοῦ τεθεάσθαι) that the rather sinewy component (τὸ νευρῶδες) of the blood vessel would have after dissection.

Even though the vessels are quickly drained of blood after killing the animal and thus are almost completely undetectable in the dissection, there are still some vascular structures that are exceptions. One is certainly the so-called Great Vessel, which is particularly visible thanks to its diameter, which gives it its name, μεγάλη, and the other is the aorta, whose visibility is not due to the diameter of the vessel but to its tendinous component, which allows this vessel to be visible even without blood in some of its sections closer to the heart in the thoracic area. In the light of such considerations formulated by Aristotle, we hypothesise that the etymological link established by ancient (medical?) experts between the signifier of the noun ἀορτή and the explanation of its meaning as rooted in its visual prominence can be explained by thinking of a verbal adjective of the verb ὁρᾶν (‘to see’) with the addition of an alpha intensivum as a prefix, ἀ-.

In naming such a vessel or explaining the etymology of the term, the material conditions of the particular visibility of its sinewy component enabled ancient physicians, or philosophers, to define the aorta as the ‘very visible’ (ἀ-ορ(α)τή) blood vessel (φλέψ), probably referring in particular to the salience of the aortic arch.

The investigation carried out here has not only made it possible to propose a solution to an unclear Aristotelian passage on the etymology of ἀορτή, but it has also elucidated the terminological negotiation that characterised intellectual debate at the time that specialised knowledge such as medical anatomy was constituted in the classical Greek world. We have shown how linguistic reflection and etymological reasoning were important heuristic tools in the anatomical investigations of the ancients: linguistic tools that could condense into the meaning of a word particular visualisations, material components, or trajectories that referred to anatomical parts inside the human being, and that were difficult if not impossible to investigate under optimal conditions.