Polybus was one of the pupils of Hippocrates

Hippocrates

Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...

, and also his son-in-law. He lived on the island of Cos

Kos

Kos or Cos is a Greek island in the south Sporades group of the Dodecanese, next to the Gulf of Gökova/Cos. It measures by , and is from the coast of Bodrum, Turkey and the ancient region of Caria. Administratively the island forms a separate municipality within the Kos peripheral unit, which is...

 in the 4th century BC. With his brothers-in-law, Thessalus

Thessalus (physician)

Thessalus, , a physician from ancient Greece, and the son of Hippocrates, the famous physician and Trichologist. He was the brother of Draco, and father of Gorgias, Hippocrates III, and Draco II. He lived in the 5th and 4th centuries BC and passed some of his time at the court of Archelaus I of...

 and Draco

Draco (physician)

Draco was the name of several physicians in the family of Hippocrates.*Draco I. Lived 5th to 4th centuries BC, was the son of Hippocrates, the famous physician . He was the brother of Thessalus. Galen tells us that some of the writings of Hippocrates was attributed to his son Draco.*Draco II...

, he was one of the founders of the Dogmatic school

Dogmatic school

The Dogmatic school of medicine was an ancient school of medicine in ancient Greece and Rome. They were the oldest of the medical sects of antiquity. They derived their name from dogma, a philosophical tenet or opinion, because they professed to follow the opinions of Hippocrates, hence they were...

 of medicine. He was sent by Hippocrates, with his fellow-pupils, during the time of the plague, to assist different cities with his medical skill. Afterwards, he remained in his native country. According to Galen, he followed implicitly the opinions and practices of Hippocrates, but the strict accuracy of this assertion has been doubted.

He has been supposed, by both ancient and modern scholars, to be the author of several works in the Hippocratic collection. Possible works include De Natura Hominis, De Genitura, De Natura Pueri, De Salubri Victus Ratione, De Affectionibus, and De Internis Affectionibus. Clement of Alexandria

Clement of Alexandria

Titus Flavius Clemens , known as Clement of Alexandria , was a Christian theologian and the head of the noted Catechetical School of Alexandria. Clement is best remembered as the teacher of Origen...

 attributes to him the treatise De Octimestri Partu, and Pseudo-Plutarch

Pseudo-Plutarch

Pseudo-Plutarch is the conventional name given to the unknown authors of a number of pseudepigrapha attributed to Plutarch.Some of these works were included in some editions of Plutarch's Moralia...

 quotes him as the author of De Septimestri Partu. De Natura Hominis (On the Nature of Man) is the earliest known text to advance a four-humor

Four humours

Four Temperaments is a theory of proto-psychology that stems from the ancient medical concept of humorism and suggests that four bodily fluids affect human personality traits and behaviors.- History and development :...

 system of blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

, phlegm

Phlegm

Phlegm is a liquid secreted by the mucous membranes of mammalians. Its definition is limited to the mucus produced by the respiratory system, excluding that from the nasal passages, and particularly that which is expelled by coughing . Phlegm is in essence a water-based gel consisting of...

, yellow bile, and black bile. Galen

Galen

Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...

, though, considers De Natura Hominis to be the work of Hippocrates himself.

Polybus is mentioned many times by Galen, chiefly in connection with different works in the Hippocratic collection. He is also mentioned by Celsus

Aulus Cornelius Celsus

Aulus Cornelius Celsus was a Roman encyclopedist, known for his extant medical work, De Medicina, which is believed to be the only surviving section of a much larger encyclopedia. The De Medicina is a primary source on diet, pharmacy, surgery and related fields, and it is one of the best sources...

, Caelius Aurelianus

Caelius Aurelianus

Caelius Aurelianus of Sicca in Numidia was a Roman physician and writer on medical topics. He is best known for his translation from Greek to Latin of a work by Soranus of Ephesus, On Acute and Chronic Diseases. He probably flourished in the 5th century, although some place him two or even three...

, and Pliny

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

.