Nature 2023 October

In biology, more than you might think can be traced back to the Ancient Greeks

For a change I am focusing, not on a particular animal or plant, but taking “the long view”. Frequently, authors refer to historical writers on animals and plants as ‘philosophers’. Scholars researching biological subjects from the late 1800s began to call themselves scientists. Writers on biological or geological topics, prior to the mid-19th century, would describe themselves as natural philosophers. ‘Natural philosophy’ was used to distinguish anything in the universe not man-made.

I sometimes come across writers on history who are prone to say “Everything can be traced back to the Ancient Greeks”. They are referring to historical characters like Aristotle. Aristotle wrote about a very wide range of subjects: the arts, politics and most prolifically about natural philosophy. He used a word for science ‘dianoia’ but this equally covered ethics, politics, the arts and poetry.

Aristotle’s writings were the result of a missed career opportunity. Aristotle’s most monumental work came about because although he had become the most celebrated pupil at Plato’s Academy, when Plato died he did not get the top job. Instead, the head of the Academy went to Plato’s nephew.

Aristotle left Athens, crossed the Aegean, and found himself, with his friend and pupil Theophrastus, on the Greek Island of Lesbos. Fortunately for Aristotle and us, the island was rich in wildlife, on land and in the sea, and was a stopping-off place for birds migrating from and to Africa, Asia and Europe. Here he investigated and documented the natural world of animals and plants in a completely new way. Aristotle, as a philosopher, described form, function and order. Despite all this deep-thinking, the belief was in spontaneous generation by their gods. Similarly, during the Christian era that followed and throughout the Medieval period there was no challenge to the belief that all animals and plants were designed at the beginning of the world by God and their look remained immutable ever since then.

Today, we would call the investigations by the Ancient Greeks biology and we could call Aristotle the first biologist. He is said to have been relentless in observing, collecting and ordering facts. He compiled his ideas on living things in his ‘Inquiries on Animals’. Aristotle’s approach was investigating ‘the what and the why’ of nature, which had hitherto been seen just part of a chaotic world. His observations on marine animals are still regarded highly in the modern zoological world, over 2000 years after he wrote about them!

Aristotle’s original works, in the Ancient Greek language, have not survived. We are lucky his words have not been lost to us thanks to the endeavours of Arabic scholars who translated the Ancient Greek into their own language.

These texts initially remained unintentionally hidden in libraries. Except by Arab, and later, Medieval and Renaissance scholars, his work was unknown, or was suppressed, as Christian faith beliefs began to flourish. The accounts in the Bible of the great flood, Noah’s dispersal of the contents of the Ark and his sons and their wives migrating to different parts of the world, provided an unchallengeable rationale why there were different kinds of plants, animals (including humans) in different places.

Between the 5th and at least 12th centuries, in the absence of alternative evidence, western philosophers generally supported this biblical explanation. The hitherto ‘lost’ Ancient text of Aristotle re-emerged in latin in the 13th century. Aristotle’s ideas about animals and plants came to the attention of Thomas Aquinas. Aristotle’s natural philosophy was rejected as heretical unless it also conformed to Christian theology.

In the 16th century Edward Wotton, an English Physician, was influenced by Aristotle’s writings on animals, particularly insects. Wotton is called the founder of the science of zoology. Sir Isaac Newton, the English philosopher, set out new methods for scientific discovery and explanation to challenge the orthodox thinking. However, this did not provide the impetus to revolutionise Aristotle’s ideas in areas such as biology, palaeontology, or geology.

The precise date for the Creation was most famously set down by the influential Archbishop James Ussher, who, in 1650, published his thesis on the age of the Earth as 9am Saturday 23 October 4004 BCE. He calculated the age of the world by literal reading of the Old Testament, counting-up the number of generations since Adam and Eve.

From the 17th century, geologists, biologists and explorers were returning with fantastical stories about plants and animals. The 18th century Industrial Revolution resulted in massive excavations for canals and railways which exposed hitherto unseen rock formations, including the giant bones of now extinct animals. In 1830 geologist Charles Lyell’s Principles of Geology literally swept away the ideas of divine intervention and Biblical flood and explanations for the discovery of large bones, fossils and stone tools that could be precisely dated to much earlier eras, as the lower down in the rock sequence they were found, the older they must be.

From the Ancient Greeks onwards there was a belief in spontaneous generation but the unchangeability of plants and animals. This was beginning to be challenged in the 18th and 19th centuries. In the 19th century Jean Baptiste Lamarck managed to integrate the beliefs of The Creation with a mechanism for ‘evolution’. This suggested an animal could pass on to its offspring the physical characteristics that it had acquired during its lifetime. The most often given example was of the long length of the giraffe’s neck caused by reaching to the leaves at the top of a tree being passed onto their offspring.

In 1831 Charles Darwin took up the invitation to be the captain’s gentleman companion on board HMS Beagle’s expedition, most importantly to The Galapagos Islands. What he saw and investigated during and after this expedition radically influenced his thinking and greatly challenged his hitherto staunchly held Christian beliefs.

Alfred Russel Wallace, during his explorations in the early 1850’s to the Malay Peninsula, set out the significant discoveries that led him to come to similar conclusions to Darwin. In 1859, Darwin published: On the Origin of Species by Means of Natural Selection.

Darwin’s book introduced the theory that animals or plants evolve over the many generations through the process of natural selection. He showed that the diversity of life by one species over time being the ancestor of two or more species a branching pattern of evolution. (Darwin’s ‘Tree of Life’). Aristotle’s immutability of living things remained influential amongst some philosophers and scientists. Even Darwin around this time praised Aristotle for being “….the most important early contributor to biological thought”.

From the 20th century onwards, Aristotle’s science is hardly ever taught or referred to. If it is, his foundation theories on biology are not given the credit they perhaps deserve. However, at least on his studies of marine biology Aristotle is praised. He correctly identified several crustaceans (crabs and lobsters), echinoderms (starfish and sea urchins), molluscs (squid and octopuses) and fish. He also recognized that whales and dolphins are mammals. As he is recognised as the first to record observations on marine life, Aristotle is referred to as the ‘father of marine biology’!

Maybe not everything but, in biology, more than you might think can be traced back to the Ancient Greeks and… in particular, to Aristotle!


Chris Brown BEM
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