Claudius Galenus
The physician who defined medicine for a millennium
129 AD – c. 216 AD
Galen of Pergamum was born in 129 AD to a wealthy architect father who gave him the best education available. He studied medicine at Pergamum, Smyrna, Corinth, and Alexandria before returning to Pergamum as physician to the gladiators — a position that gave him unparalleled experience with trauma surgery. Around 162 AD he moved to Rome, where he became physician to the emperors Marcus Aurelius, Commodus, and Septimius Severus. He died around 216 AD.
Galen was the most prolific medical writer of antiquity. Hundreds of treatises survive — on anatomy, physiology, pathology, pharmacology, therapeutics, and medical philosophy. De naturalibus facultatibus (On the Natural Faculties) is a key work that sets out his theory of the body's innate powers of attraction, retention, alteration, and expulsion. His system, built on Hippocratic humoral theory but vastly elaborated with his own anatomical discoveries (mostly from animal dissection, since human dissection was rarely practised), dominated Western and Islamic medicine for over 1,300 years.
Galen was brilliant, industrious, and spectacularly arrogant. He never missed an opportunity to point out the errors of his predecessors and rivals. The arrogance was not entirely unjustified — his anatomical knowledge was genuinely superior to anyone else's in antiquity.
A practical guide to the method of healing, addressed to Galen's student Glaucon. Galen distils his therapeutic principles into a form suitable for a...
Galen's passionate exhortation to young men to study the arts and sciences. He argues that intellectual cultivation is essential to human excellence a...
A polemical work in which Galen attacks the medical opinions of Julianus, who had written a commentary on the Hippocratic Aphorisms. Galen defends his...
A treatise on the classification of fevers by their periodic patterns. Galen disputes rival theories about fever types and recurrence cycles, establis...
A polemic against the physician Lycus, criticising his anatomical and physiological errors. Galen demonstrates through detailed anatomical argument th...
A short treatise addressing the question of whether arteries contain blood. Galen argues against the Erasistratean view that arteries carry only pneum...
Galen's systematic introduction to the art of medicine. The Ars Medica provides a comprehensive overview of medical theory — the elements, temperament...
A comprehensive treatise on the nutritional properties of foods. Galen classifies foods by their effects on the body's temperament — heating, cooling,...
Galen's monumental guide to dissection. Across nine books, he provides detailed instructions for anatomical investigation of every bodily system — mus...
A treatise on recognising and correcting errors of judgement. Galen examines how intellectual mistakes arise from passion, habit, and false reasoning,...
A treatise on the nature, causes, and treatment of black bile and the melancholic condition. Galen examines how an excess of black bile produces disea...
A short treatise defining what constitutes good physical condition. Galen argues that optimal bodily health is a precise balance of the qualities — no...
A systematic classification of the causes of disease. Galen identifies three categories — immediate, antecedent, and predisposing causes — and examine...
A detailed treatise on the pulse as a diagnostic tool. Galen examines what causes different types of pulse, connecting variations in rhythm, strength,...
A short treatise on the causes and mechanics of breathing. Galen investigates what drives respiration and how the respiratory system functions, drawin...
A treatise examining the comatose state as described in the Hippocratic writings. Galen interprets and expands upon Hippocratic observations about alt...
A massive pharmacological work in ten books, organising compound medications by the body part they treat. From head to feet, Galen catalogues remedies...
An introductory treatise addressed to Patrophilus, setting out the fundamental principles on which the art of medicine is constituted. Galen defines m...
A treatise on the role of habit and custom in health and disease. Galen examines how habitual behaviours affect bodily temperament and argues that med...
Galen's major work on medical crises — the critical turning points in acute diseases. He examines how to predict when a crisis will occur, what form i...
A treatise defending and explaining the practice of therapeutic bloodletting. Galen argues for venesection as a treatment for plethora and various acu...
A treatise on critical days — the specific days in the course of a disease when significant changes are expected. Galen develops a predictive system b...
A systematic classification of fevers into their distinct types. Galen distinguishes ephemeral, hectic, and putrid fevers, examining the causes, chara...
A detailed treatise classifying the different types of pulse. Galen identifies and names dozens of pulse varieties by their size, speed, frequency, rh...
A treatise on respiratory disorders. Galen examines the causes and varieties of breathing difficulties — from asthma to pleurisy — analysing the mecha...
A treatise on the art of pulse diagnosis. Galen teaches how to read the pulse accurately, distinguishing genuine variations from artefacts of techniqu...
A short treatise on medical diagnosis through dreams. Galen argues that dreams can reveal the body's internal state — an overheated patient dreams of...
An early treatise in which Galen examines the Hippocratic theory of the elements. He analyses what Hippocrates meant by the primary constituents of th...
A treatise on medical empiricism, surviving only in a medieval Arabic translation. Galen examines the role of experience versus reason in medical know...
A treatise on embryological development. Galen examines how the foetus takes shape in the womb, tracing the formation of organs, limbs, and bodily sys...
A practical treatise on minor surgical procedures — the use of leeches, cupping, scarification, and incision for therapeutic bloodletting. Galen provi...
A treatise on shoulder dislocations that Hippocrates did not describe. Galen identifies additional modes of shoulder displacement beyond those in the...
A treatise on uneven dyskrasia — a condition where different parts of the body have different imbalances of the qualities. Galen examines how localise...
A short anatomical treatise on the organ of smell. Galen investigates the structure of the nasal passages and olfactory apparatus, explaining how odou...
One of Galen's most important clinical works. Across six books, he examines how to identify the location of disease within the body — using symptoms,...
A short treatise on wasting disease (marasmus). Galen examines the progressive drying and emaciation of the body, its causes, and the limited treatmen...
Galen's masterwork on therapeutic method, spanning fourteen books. He develops a comprehensive system for treating disease based on rational principle...
A systematic classification of diseases by their essential differences. Galen distinguishes diseases of similar parts from diseases of organic parts,...
A treatise on the timing and duration of diseases. Galen examines how to predict the course of an illness by observing the sequence and timing of its...
A treatise on the mechanics of muscular movement. Galen examines how muscles contract and relax, how nerves transmit the impulse to move, and how the...
A practical guide to muscle dissection for beginners. Galen provides systematic instructions for identifying and exposing every muscle in the body, wr...
A treatise on the natural faculties of the body — attraction, retention, and expulsion. Galen defends Hippocratic medicine against rival schools and e...
An anatomical treatise on the dissection of nerves. Galen traces the course of every nerve from the brain and spinal cord to its termination, establis...
A short treatise defining the optimal constitution of the human body. Galen describes the ideal balance of qualities and proportions that constitutes...
A brief treatise defending the value of systematic instruction in medicine. Galen argues against those who claim that medicine can be learned through...
An introductory treatise on osteology for students. Galen provides a systematic description of every bone in the human body, covering its shape, size,...
A short treatise advocating exercise with the small ball as the ideal form of physical training. Galen argues that ball games exercise every part of t...
Galen's monumental work reconciling Hippocratic medicine with Platonic philosophy. Across nine books, he demonstrates that the doctrines of the two gr...
A treatise on plethora — the condition of excessive fullness in the body's vessels. Galen examines its causes, symptoms, and dangers, and argues for b...
A clinical treatise addressed to Epigenus, demonstrating Galen's powers of medical prognosis. Through detailed case studies, he shows how a skilled ph...
A treatise on prognostic pulse diagnosis. Galen teaches how to use the pulse to predict the future course of a disease — whether it will worsen, impro...
A treatise on recognising and treating the passions of the soul. Galen offers a programme of philosophical self-examination and moral improvement, arg...
A short treatise on the therapeutic uses of barley gruel (ptisane). Galen examines the Hippocratic recommendations for this staple of ancient dietetic...
An introductory treatise on the pulse for medical students. Galen explains the fundamentals of pulse-taking — what to feel for, how to interpret diffe...
A treatise on the properties and appropriate uses of purgative drugs. Galen classifies cathartic medications by their strength and specificity, explai...
A dietetic treatise classifying foods by whether they produce good or bad humours in the body. Galen evaluates common foods — breads, vegetables, meat...
A comprehensive treatise on hygiene and the preservation of health across six books. Galen prescribes regimens of diet, exercise, bathing, and sleep a...
An introductory treatise examining the three main medical sects of antiquity — the Rationalists, the Empiricists, and the Methodists. Galen describes...
The first six books of Galen's massive pharmacological encyclopaedia, classifying simple drugs by their properties. Each drug is evaluated for its war...
A treatise on logical fallacies arising from ambiguities of language. Galen examines how the same words can be used in different senses, producing spe...
A fragmentary treatise examining the material substrate of the natural faculties. Galen investigates the physical basis of the body's vital powers — n...
A systematic treatise on the causes of symptoms. Galen examines how different diseases produce their characteristic symptoms, tracing the causal chain...
A treatise classifying symptoms into their fundamental types. Galen distinguishes symptoms affecting function, activity, and excretion, creating a sys...
A foundational treatise on the theory of bodily temperaments. Galen develops his influential doctrine that health depends on the balance of four prima...
A treatise on the medicinal compound known as theriac, addressed to Piso. Galen describes the composition, preparation, and therapeutic uses of this f...
A treatise on the overall timing of diseases, distinguishing the stages through which an illness progresses — onset, increase, acme, and decline. Gale...
A treatise on four related neurological conditions — tremor, palpitation, convulsion, and rigor. Galen examines the causes and mechanisms of each, dis...
A treatise on tumours and abnormal swellings. Galen classifies these conditions by their underlying causes — inflammation, excess of a particular humo...
The first eleven books of Galen's greatest anatomical work. De Usu Partium demonstrates that every structure in the body is perfectly designed for its...
A treatise on the function of the pulse. Galen argues that the pulse serves to regulate the body's innate heat by drawing in cooling air and expelling...
An anatomical treatise on the dissection of the uterus. Galen describes the structure of the female reproductive organs based on animal dissection, wi...
A treatise on the function and necessity of breathing. Galen examines why respiration is essential to life, arguing that it serves both to cool the in...
A polemical treatise against the Erasistratean physicians practising in Rome, who rejected bloodletting. Galen argues forcefully that venesection is a...
A polemical treatise against Erasistratus' rejection of bloodletting. Galen attacks the theoretical foundations of the Erasistratean position, arguing...
An anatomical treatise on the dissection of veins and arteries. Galen traces the course of the major blood vessels through the body, providing detaile...
A short treatise on sexual intercourse and its effects on health. Galen examines the physiological consequences of sexual activity, recommending moder...
A short dietetic treatise on the thinning diet. Galen prescribes a regimen designed to reduce excess flesh and bodily bulk, specifying which foods, ex...
Galen's commentary on the Hippocratic Aphorisms across seven books. He explains, contextualises, and sometimes disputes each of the famous medical max...
Galen's commentary on the Hippocratic treatise On Joints. He explicates Hippocrates' surgical instructions for treating dislocations and fractures of...
Galen's commentary on the Hippocratic treatise On Fractures. He explains the principles of fracture management laid down by Hippocrates, supplementing...
Galen's commentary on the Hippocratic treatise On the Nature of Man. He interprets and defends Hippocrates' theory of the four humours, treating this...
Galen's commentary on the Hippocratic treatise On the Surgery (or Doctor's Workshop). He explains the practical instructions on bandaging, surgical po...
Galen's commentary on the Hippocratic treatise On Regimen in Acute Diseases. He examines Hippocrates' dietary prescriptions for patients with acute il...
Galen's commentary on the first book of the Hippocratic Epidemics. He analyses the clinical case histories recorded by Hippocrates, interpreting the s...
Galen's commentary on the Hippocratic Prognostic. He explains Hippocrates' methods for predicting the course of diseases from observable signs, treati...
Galen's commentary on the Hippocratic treatise on healthy living for private individuals. He interprets and expands upon the dietary and lifestyle rec...
Galen's introduction to formal logic. A clear and systematic treatise covering propositions, syllogisms, and methods of proof — one of the most access...
A clinical case report in which Galen prescribes treatment for a boy suffering from epilepsy. The treatise illustrates his diagnostic method and thera...
A treatise arguing that moral character depends on bodily temperament. Galen makes the provocative claim that the soul's dispositions follow the body'...
A short treatise arguing that the best physician must also be a philosopher. Galen contends that logic, ethics, and natural philosophy are all indispe...
A practical treatise on when and how to administer purgative drugs. Galen specifies which patients should be purged, which cathartics to use for each...
A concise summary of Galen's extensive writings on the pulse. This synopsis distils the key points from his major pulse treatises into a manageable ov...
A treatise debating whether hygiene belongs to medicine or to gymnastics. Galen argues that the preservation of health falls primarily within the phys...