by PM Dunn: Aristotle was one of the greatest philosophers and scientists the world has ever seen.  He was born in 384bc at Stagirus, a Greek seaport on the coast of Thrace. His father, Nichomachus, court physician to King Amyntus II of Macedon, died while he was still a boy, and his guardian, Proxenus, sent him to complete his education at the age of 17 in Plato’s Academy in Athens.

He remained there for the next 20 years, first as a pupil and later as a teacher. Plato and Aristotle recognised each other’s outstanding qualities, but they had frequent arguments and disagreements. Whereas Plato believed that reality existed in ideas, knowable only through reflection and inspiration, Aristotle saw ultimate reality in physical objects, knowable through the experience of the five senses. He believed that every problem had an objective solution. His was a scientific approach. Of his master he wrote: “Plato is my friend but truth is much more”.

When Plato died in 347 bc, Aristotle, aged 37, was not appointed to succeed him. Perhaps his differences with Plato were too great. He then left Athens to spend the next five years in Asia Minor at the court of Hermeas, ruler of Atarneus in Mysia, whose niece and adopted daughter, Pythias, he married. In later life he married a second time a woman named Perpyllis, who bore him a son, named Nichomachus after his father. In Asia Minor and later in Mytilene (Lesbos), Aristotle pursued his studies in biology and natural history until, in 342 bc, he was recalled to Macedon by Phillip II (King Amyntas’ son) to act as tutor to his 14 year old son Alexander. Seven years later, in 336 bc, Phillip was assassinated, and the following year Alexander, now king, set out on his conquest of the Persian Empire. At this time, Aristotle at the age of 49 returned to Athens to found his own school of philosophy, The Lyceum. It was nicknamed the “peripatetic school” because of Aristotle’s practice of lecturing his students while walking around the school’s garden. Besides teaching, Aristotle amassed a large collection of manuscripts, which later found their way to the library in Alexandria. He also cultivated a botanical garden. His disciple and successor, Theophrastus of Eresos (370–287 bc) later based his De historia plantarum on this garden, listing 500 plants.

When news of Alexander’s death in Babylon reached Athens in 323 bc, Aristotle, fearing an anti‐Macedonian reaction, prudently withdrew from Athens to Chalcis in Euboea, his mother’s home town. There the following year, 322 bc, he died of a stomach illness. He was 62.

Aristotle’s lectures were collected into nearly 150 volumes and represented an encyclopaedia of the knowledge of his day, much of it indeed his own contribution. Unfortunately, less than a third of his writings have survived. Although Aristotle’s most important work was on biology, he also dealt with logic, metaphysics, psychology, meteorology, politics, literary criticism, poetry, drama, and ethics. Although he was not a doctor, his contributions to medicine were immense. He was the first to treat systematically the fields of botany, zoology, anatomy, embryology, teratology, and physiology. Aristotle was assisted by his great faith in nature, writing: “In all things of nature there is something of the marvellous”, “Nature does nothing uselessly”, and “If one way be better than another, that you may be sure is nature’s way.”

Starting as he did virtually from scratch, it is hardly surprising that some of Aristotle’s explanations as to how the human body functioned were incorrect. For instance, like Hippocrates, he subscribed to the humeral theory of disease holding that there were four primary fundamental “qualities” in life: hot, cold, wet, and dry. These met in binary combination to constitute the four “elements”: earth, air, fire, and water, represented respectively by black bile, yellow bile, blood, and phlegm. The body was thought to be composed of these “humours”, which were responsible for the temperaments: melancholy, choleric, sanguine, and phlegmatic. Disorders of the human body were thought to be caused by an upset in the balance of these humours.1 Unfortunately his fame and authority were so great that these concepts persisted for 2000 years until overturned after the Renaissance in the 16th century. This was hardly the fault of Aristotle, who was himself no believer in blind obedience to authority.

Aristotle was a great classifier and codifier. In his effort to develop a strong taxonomic scheme, he noticed important similarities and differences between various zoological forms. He arranged these upon a basis of increasing perfection, extending from lower to higher animals. In its way, this was a theory of evolution. He also developed a coherent theory of generation, believing that the mammalian egg was formed in the uterus as a result of the activation of menstrual blood by male semen. “Sex” he wrote “is determined by the male principle already contained in the semen. If this is not strong enough, then the opposite must necessarily come into existence, and the opposite of man is woman.”

Being unable to study the internal structure of the human body, Aristotle turned to the study of animals, founding the science of comparative anatomy. He is said to have dissected over 50 different species, writing: “The inner parts of man are uncertain and unknown, wherefore we must consider those parts of other animals which bear any similarity to those of man.” For his embryological studies he used the chick embryo, describing among other observations the first sign of the embryo, the early development of the heart and great vessels, the beating of the embryo’s heart, and the differences between arteries and veins.

In Aristotle’s day, midwifery was the undisputed province of the midwives, though it was common practice for them to seek assistance from a doctor. Midwives had to be mothers who were past the age of childbearing. One of their functions was to advise men on which girls would be likely to produce the best offspring. They undertook vaginal examinations and were allowed to prescribe drugs, to procure abortion, and to bring on birth prematurely. Another duty was to show the newborn baby to the father. If he was then prepared to recognise the child as his own, he lifted it up for a moment and then handed it back to the midwife. Perhaps their most important responsibility, though, was on when and how to cut the umbilical cord. This was usually delayed until after the afterbirth had been expelled. Any delay in delivery of the placenta was managed by tying weights to the cord and by giving the woman powders to make her sneeze violently.