From the many manuscripts and artefacts that have remained from medieval Islamic societies, it becomes evident how great the contribution of intellectuals in all areas of science used to be. Many sciences like astronomy, mathematics, medicine, optics, botany and pharmacology blossomed all across the Islamic world and therefore, it is important to have a better understanding of the scientific developments in the past that leave their impact in modern society today.
One of the most famous scholars was the Persian polymath Nasir al-Din al-Tusi. He was a scholar whose knowledge spanned across a very large range of subjects: he was an architect, philosopher, physician, scientist, theologian, chemist, biologist, astronomer, mathematician and philosopher. Al-Tusi was born in northeaster Iran, Tus, where he started his education. When the Mongols conquered this area in the 13th century, he became the scientific advisor under the rule of the Mongolian conqueror Hulagu Khan. After his service, he was allowed to establish his own observatory, which became a first-rate library where al-Tusi staffed his institution with Islamic and Chinese scholars.
Throughout his life, he wrote about 150 different works in Arabic and Persian and edited works from famous scholars such as Euclid and Archimedes. He is mostly known for his contributions in mathematics and astronomy. In his book Tadhkirah fi’ilm al-hay’a, he described a geometric construction, the ‘al-Tusi couple’, for producing rectilinear motion from one point on one circle rolling inside another. This way, he produced a system in which orbits are described by a uniform circular motion and this was a model that eventually inspired Nicolaus Copernicus for his own astronomical models.
However, one other notable contribution of al-Tusi is his theory of evolution. He proposed this theory about 600 years before Charles Darwin conceived of evolution. In his work ‘Akhlaq-i-Nasri’, he explains how the universe once consisted of small and similar elements. Then, he puts the emphasis on the internal variability that started to appear between these elements. Some substances started to grow faster and became different from the other substances around them. This way, elements turned into minerals, plants, animals and humans. These are the types of living things that Tusi described.
He wrote how depending on the environment animals are in, they can have various features like horns-spear and teeth, claws-knife and needle, feet and hoofs-cudgel:
“Animals that have no other means of defence (as the gazelle and fox) protect themselves with the help of flight and cunning…some of them, for example bees, ants and some bird species, have united in communities in order to protect themselves and help each other.”
The animals and the plants do differ from each other and he explained this as follows:
“Animals are higher than plants, because they are able to move consciously, go after food, find and eat useful things…there are many differences between the animal and plant species…first of all, the animal kingdom is more complicated. Besides, reason is the most beneficial feature of animals. Owing to reason, they can learn new things and adopt new, non-inherent abilities. For example, the trained horse or hunting falcon is at a higher point of development in the animal world. The first steps of human perfection begin from here.”
Then, Nasir al Din al Tusi explains the evolved human being from the advanced animals:
“Such humans [probably anthropoid apes] live in the Western Sudan and other distant corners of the world. They are close to animals by their habits, deeds and behaviour…the human has features that distinguish him from other creatures, but he has other features that unite him with the animal world, vegetable kingdom or even with the inanimate bodies…before [the creation of humans], all differences between organisms were of the natural origin. The next step will be associated with spiritual perfection, will, observation and knowledge…all these facts prove that the human being is placed on the middle step of the evolutionary stairway. According to his inherent nature, the human is related to the lower beings, and only with the help of his will can he reach the higher development level.”
What is a notable difference between the theory of evolution proposed by Darwin and the theory of evolution of Nasir al Din al Tusi, is that the latter is related to ideas about man’s higher spiritual development. This theory shows how man, by allowing the spiritual aspects of himself to grow, actually develops that what makes him unique and different from the other species on earth. This is what man is capable of doing through his free will, thoughts and senses. Al-Tusi proved through his theory how the bias of religion contradicting with science is not true; In his case, it was Islam that triggered him to think about his origin and awakened his curiosity to learn about all disciplines in life. It is thanks to the mentality of scholars like him, that we are where we are today in science and why science is always growing.