The Hippocratic Corpus is a collection of approximately sixty medical texts, all in the Ionic Greek dialect, attributed to Hippocrates of Cos, the famous physician mentioned by Plato (Phdr. 270c) and Aristotle (Pol. 1326a15). Since antiquity, it has been recognized that Hippocrates could not have authored all those texts, which vary vastly in style and sometimes present contradictory views. Most Hippocratic treatises can be dated to the 5th or 4th century bce, but some are later, such as the anatomical text On the Heart, which dates to 3rd century bce.

Debating the authenticity of Hippocratic wraitings, the so-called “Hippocratic question,” has been one of the main tenets of the extensive exegetical tradition that started in the 3rd century bce at Alexandria, perhaps with Herophilus of Chalcedon. One of the key figures in this tradition, Galen of Pergamum, discussed authorship at length in his Hippocratic commentaries, and presumably too in his lost treatise On the Genuine Works of Hippocrates. The Hippocratic question remained at the centre of scholarship for centuries; it was a key organizing principle in the monumental ten-volume edition (1839–1863) by the French scholar Émile Littré, who considered On Ancient Medicine as the essence of Hippocrates’s’ work.

Interest in the authorship question waned in the second half of the 20th century. Attempts were then made to divide the Hippocratic writings into Coan and Cnidian categories, that is, groupings of texts originating from supposed schools of medicine geographically based in Cos and Cnidus. Coan medicine was presented as more rational, Cnidian medicine as more empirical. Current scholarship focuses less on the vexed question of authenticity and more on the fluidity of the very notion of Hippocratic Corpus. Indeed, the corpus as we know it is the product of a canonization process that culminated in the Renaissance, in particular with the Aldine edition of 1526. The corpus is today considered as a cultural artefact, to be read alongside other contemporary sources, both textual and material. As such, the corpus and its texts lend themselves well to interdisciplinary approaches which bring together philology, literary analysis, philosophy, medicine, and history.

Attempts at classifying Hippocratic texts by subject matter have been made since antiquity. The lexicographer Erotian divided the works by subject matter into those concerned with signs; those on nature and aetiology; those devoted to the art, the technē, of medicine; those on therapy (which he divided into surgery and dietetics); and those that are “blended,” mixed in their approach. As this last category demonstrates, some Hippocratic texts defy any attempt at classification. Modern classifications by topics give more prominence to gynaecology (subsumed under “therapy” in Erotian’s categorization), which constitutes a significant proportion of the corpus and which has received much scholarly attention in recent decades. The gynaecological treatises are unusual in that several include numerous pharmacological recipes; pharmacology, as Erotian’s division shows, is not particularly prominent in the other parts of the corpus. Hippocratic medicine is best characterized as dietetic medicine, one that takes into consideration the everyday habits of patients: their diets, sleep, exercise, sexual activity, and so on.

The principles of dietetic medicine are powerfully expressed in the Oath, the Hippocratic text that has had the largest reception. The Oath presents medicine as a technē, an art, that is passed on from father to son, or from a master to his apprentice, under the protection of Apollo, Asclepius, and his acolytes. The Oath states that some actions fall outside the technē of the physician (the iatros): giving anyone a deadly drug; giving a woman a destructive pessary; and cutting for kidney stones. With regards to cutting, the Oath acknowledged that there were people who specialized in surgery to whom this task should be left, even though, as treatises such as On Fistulas and On Haemorrhoids show, some Hippocratic authors did use the scalpel. There also existed in antiquity people whose technē centred on dangerous plants (the root-cutters and root-sellers) and the care of women, which included abortion (the midwives). The Oath, then, attempted to delineate the boundaries of a physician’s technē against those of other experts. This method is illustrated throughout the corpus. The author of On the Sacred Disease defended his art against the practices of “magicians, purifiers, charlatans, and quacks.” Other Hippocratic authors openly criticized other iatroi (physicians) for engaging in practices that fell short of their ideals.

In the competitive context of Hippocratic medicine, establishing one’s reputation was essential. The Oath ends with a promise of good reputation for the physician who carried out its principles. Several other short deontological texts (On Decorum; The Law; On the Physician) describe the behaviour expected from the reputable physician. One means for doctors to achieve good repute and gain clients was through prognosis, an art to which several Hippocratic treatises are devoted (Prognostic; Prorrhetic 1 and 2; Coan Prognoses), and which was more important to ancient doctors than diagnosis. Prognostication involved forecasting the future of a patient’s illness, but also knowing its past and present. It aimed at finding the best possible treatment or deciding that a disease was incurable, with little apparent regard for the psychological impact on the patient of receiving bad news. The group of seven treatises entitled Epidemics includes numerous case histories, where the symptoms and painful death of the patients are dispassionately depicted. Yet it is at times possible to discern traces of compassion and attention to the patient’s voice in the corpus.

Aetiology, which underpins prognosis and treatment, is also well represented in the corpus. Hippocratic authors searched for the causes of diseases in nature, physis, rejecting divine causation. They saw health as a state of balance which could be disrupted by causes that were either internal (humours) or external (such as the environment, activities, injuries) to the patient. The concept of humours is present in numerous treatises, but it is only in On the Nature of Man that the well-known theory of the four humours—blood, phlegm, yellow bile, and black bile—is expounded. There are also four humours in On Diseases 4, but in this treatise a watery humour replaces black bile.

Hippocratic aetiology owed much to the theories of early Greek philosophers, with whose theories the Hippocratic writers engaged. Only two philosophers are mentioned by name in the corpus, both in a critical fashion: Empedocles in On Ancient Medicine, and Melissus in On the Nature of Man. Allusions to other philosophers in the corpus are less explicit, but one can recognize oblique references to the theories of Alcmaeon, Anaxagoras, Anaximander, Democritus, Diogenes of Apollonia, Empedocles, and Xenophanes. Democritus features prominently in the Hippocratic Letters, a late epistolographic novella in which Hippocrates is called upon to treat the philosopher, who inappropriately laughs at everything.

From a stylistic point of view, there is huge variety within the corpus. Some treatises, such as On Winds or The Art, are well-polished texts that share much with epideictic speeches, as represented in the fragments of Gorgias. At the other end of the spectrum, texts, such as the nosological treatises and the gynaecological treatises, are miscellaneous collections of technical material that can be difficult to summarize. An aphoristic style is represented in several Hippocratic texts, of which Aphorisms is the best known. Overlap in content is frequent within the corpus, pointing to processes of rewriting and reshaping pre-existing material. Several Hippocratic authors expressed themselves in the first person, imparting their authority to reused material.

The author of the nosological treatise On Affections claimed to write for laypeople. If this assertion can be trusted, laypeople who were literate seemingly could deal with a relatively high level of medical technicality. This was indeed the case of non-medical authors such as Thucydides, Aristophanes, and Plato, who all engaged with medical theories and material in their respective works.