Teratology: “Monster” as a medical term

Note: Many medical terms used in the past – even through the first half of the 20th century – are words that we find insensitive or cruel today. Like any field of history, it is important to keep in mind the time period in which the texts were written and to not pin our 21st-century beliefs on those of the past. As historians, it is up to us to observe, not to judge.

Paré, Ambroise. Les oeuvres d’Ambroise Paré. Paris: Macé, 1614: 733. Call number: ZEa 9f

At one time,  the word “monster” was used to describe people with medical anomalies, not just fabulous creatures out of legends.  The fascination with so-called “monsters” dates back at least to antiquity. Aristotle (384 – 322 BC), a Greek philosopher and scientist; Pliny the Elder (AD 23 – August 25, AD 79), a Roman philosopher; and Saint Augustine of Hippo (13 November 354 – 28 August 430), an early Christian theologian and philosopher, all discuss the monstrous in their works.

In the second half of the 15th century, the printing press helped spread knowledge like never before, and books on monsters became more popular.  Some monsters are animals that we know today, although they may not recognizable.  Ambroise Paré’s (1510-1590) Les oeuvres d’Ambroise Paré includes an astonishing number of monsters, both animal and human, real and legendary. In his book he recorded creatures like seahorses, crocodiles, and unicorns, along with conjoined twins, men born without limbs, and strange human-animal hybrids.  It was believed that the birth of these monsters and “prodigies” often foretold an impending disaster.

In 1605, female conjoined twins were born in Paris. The story of the twins was published at least four times, and this was the first attempt at explaining a monstrous birth with scientific reasoning, rather than superstition. It was during the 17th century that curiosity began to replace the suspicion with which monsters were perceived.  Scholars were more inclined to use reason in an attempt to explain the world around them.

This new, scientific attitude to the world continued throughout the 18th century.  The 18th century saw the formation of numerous scholarly societies, which in turn led to more detailed medical studies of monstrous births and other anomalies. It was during the early 19th century when Isidore Geoffrey St. Hilaire coined the term teratology (the study of abnormalities of physiological development).  As medical knowledge continued to grow and monstrous births were studied with a more scientific attitude, the attitude towards the “monsters” themselves also changed. Once seen as creatures to be feared, people born with physical anomalies were, for the most part, seen as opportunities for the field of medicine to advance.

Even with the move to a more logical, scientific search for knowledge, it wasn’t until the early 20th century that the word “monster” stopped being used to describe people born with physical abnormalities. It was even later – during the second half of the 20th century – when carnivals stopped exhibiting “freaks” as sideshows. Today, of course, the words “monster” and “freak” are not used to describe people with medical anomalies, but that wasn’t the case in fairly recent history.

The links below will direct you to the catalog record or finding aid of the resource listed.  Remember to check our library catalog and finding aids – these are only some of the great sources we have about teratology and the concept of “monster”!

Primary sources

book-croppedThe works of Ambrose Parey
by Ambroise Paré, 1575; translated into English, 1678
Call number: ZEa 9b.2b


book-croppedThe expert midwife; or, An excellent and most necessary treatise of the generation and birth of man
by Jakob Rüff, 1554; translated into English, 1637
Call number: GGc 14.1


book-croppedA most certaine and true relation of a strange monster or serpent found in the left ventricle of the heart of John Pennant
by Edward May, 1639
Call number: MMi 229


book-croppedAnomalies and curiosities of medicine
by George Gould and Walter Pyle, 1937 [c 1896]
Call number: WZ 308 G696a 1937a


book-croppedHuman monstrosities
by Barton Cooke Hirst and George Piersol, 1891
Call number: ZCd 12


book-croppedThe mystery and lore of monsters: with accounts of some giants, dwarfs, and prodigies
by C.J.S. Thompson, 1930
Call number: Cd 44

Secondary sources

magazine“A Brief History of Teratology to the Early 20th Century,” from Teratology, vol. 4, no. 2
by Mark V. Barrow, May 1971


book-croppedThe Monster in the Machine: Magic, Medicine, and the Marvelous in the Time of the Scientific Revolution
by Zakiya Hanafi, 2000
Call number: QS 675 H233m 2000


book-croppedThe body of Frankenstein’s monster: essays in myth and medicine
by Cecil Helman, 1992
Call number: WZ 309 H478b 1992


“Tracing Monsters Across Medicine,” from Fugitive Leaves: A blog from The Historical Medical Library of The College of Physicians of Philadelphia.
by Shane Miller, 13 October 2015


book-croppedSigns and Portents: Monstrous Births from the Middle Ages to the Enlightenment
by Dudley Wilson, 1993
Call number: WZ 308 W747s 1993


*Content written by Chrissie Perella, Archivist