An intelligent man from modern-day Uzbekistan formulated laws of geology hundreds of years before any European.

(Cover Image Credit: Uzbekistan landscape by Artem Bryzgalov on Unsplash CC0. Potrait of Ibn Sina, public domain.)

A young physician was interested in the natural world, especially with the rock formations around his homeland. He wondered how they were formed. His curiosity drew him to a nearby riverbed where he noticed the lackadaisical tumbling of sand grains and the slow deposition of mud along the banks. He deduced, correctly, that the steady processes he observed, applied over millions of years, must have created the local rocks. The concept is now known as “uniformitarianism,” one of geology’s most important principles.¹

Those of you who have sat in an introductory geology course are sure that I am talking about James Hutton, the “father of geology.” Hutton was a Scottish physician turned geologist known for his foundational publications on geology, especially uniformitarianism. But by now my astute readers know that I’m not actually talking about Hutton.

Abu Ali al-Huysayn bin Abdillah ibn al-Haan bin Ali ibn Sina (أبو علي الحسين بن عبد الله بن الحسن بن علي بن سينا) or Ibn Sina (often Latinized as Avicenna), wrote about uniformitarianism 800 years before Hutton.¹

Ibn Sina authored some of the earliest known works on paleontology and geology.¹ He was skilled in philosophy, theology, medicine, physics, chemistry, astronomy, and meteorology. His book on medicine became the primary reference for physicians in Europe until the mid 1700’s.² Ibn Sina’s prolific writings impacted science across the world. Yet despite his importance, and his notoriety in Central Asia and the Middle East, he is still largely an unknown figure in Europe and North America. I am hopefully going to change that by writing about Ibn Sina for two main posts and two shorter “Micro Musings.” In part 1 of that series, I discuss Ibn Sina, his life, and his role in the Earth sciences.

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Persian Polymath and the World’s Biggest Aristotle Fanboy

Ibn Sina was born in present-day Uzbekistan, which at that time was ruled over by a Persian dynasty (the Samanids). Ibn Sina had a knack for learning, and, in his own words, he became interested in philosophy and science at an early age.

“I memorized the Quran and read literature and mastered logic and philosophy then wanted to study medicine, I did within the least possible period of time because it is not the hard science. [sic] And this experience was beyond description beneficial. And when I mastered logic and metaphysics I stated again to explore the science of God.”

Ibn Sina³

Ibn Sina began his career as a scientist after he saved the life of the Sultan of Bukhara:

“One day, Sultan of Bukhara, Noah bin Mansour Alsmandi, got sick and his doctors couldn’t cure him so he called and brought me, and treated him. Then I asked him to authorize me to enter his library and read some books, his library was massively great. I read many beneficial books about wisdom. I was eighteen years old.”

Ibn Sina³

The access to the Sultan’s library opened Ibn Sina up to a world of ancient texts on philosophy, medicine, and natural science. Islamic libraries contained thousands of books from across the world. Most importantly, they contained texts from Greek writers including Aristotle.^2,3

I like to think of Ibn Sina as the world’s biggest Aristotle fanboy. He based his entire scientific outlook on the writings of the ancient Greek writer. Many, if not most, of his works directly reference Aristotle². He went to great lengths to defend Aristotle from others who pointed out that the Greek philosopher was not always correct.⁴

Many of his writings centered around philosophy and theology. He especially wanted to reconcile his Aristotelian worldview that logic and reasoning should be used to study everything with his Islamic faith. Even though he often attempted to explain scientific observations in the context of Islam, he never dismissed evidence.^2,4  

Ibn Sina was intelligent, something he was quick to point out to others. However, he knew his own limitations. He acknowledged that he was not as well studied in certain subjects, especially mathematics.⁴ He cited contemporaries in his writings, and he favored review of scientific work by peers (predating the modern notion of peer-review by hundreds of years).^2,4

Ibn Sina’s interest in Aristotle led him to develop a strong desire to understand the physical world. He studied the geology and paleontology of his homeland in modern-day Uzbekistan. His geologic work, outlined in his work the “Book of Healing,” is what makes me consider him the true “father” of geology.

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A “Founding Father” of Geology and Paleontology

In the Book of Healing, Ibn Sina wrote the geology and paleontology of the Amu Darya River area of Uzbekistan along the border of modern-day Turkmenistan and Afghanistan.

Ibn Sina was one of the first geologists to comment on what is now called the “rock cycle” which describes how rocks are formed and then transformed from one type to another through erosion, weathering, sedimentation, and then ultimately deep burial and melting. He identified two of the three main rock types (sedimentary and igneous) when he mentioned one type of rock “being formed from water and mud” and the other “from fire.”¹ He failed to recognize metamorphic rocks, but the world at large did not know of their existence until the invention of microscopy.¹

Ibn Sina wrote on “formation of stones in great bulk” and mountains in which he describes uniformitarianism. In his writings, he conveys a sense of the vastness of geologic time long before anyone knew the Earth was billions of years old.

The formation of stones in abundance is either at once due to intense heat [note from the translator: probably referring to arid climate] over vast mud area; or little by little through a sequence of days most probably from agglutinative clay which slowly dried and petrified during ages of which we have no record. It seems likely that this habitable world was in former days uninhabitable and, indeed, submerged beneath the sea. Then becoming exposed little by little, it petrified in the course of ages the limits of which history has not preserved.

Ibn Sina, Book of Healing¹

He then added some information related to paleontology. He discovered parts of “aquatic animals” including shells that were mineralized on the mountainsides he had investigated. He correctly concluded that the land was once “covered by the sea.” He then also correctly inferred that it was water in the rock that petrified the animal remains into fossil material, although he did not specify how this action took place. He ultimately failed to understand exactly how the process worked, that minerals in the water replace the skeletal material, but his description is fairly accurate.

If what is said concerning the petrifaction of animals and plants is true, the cause of this (phenomenon) is a powerful mineralizing and petrifying virtue which arises in certain stony spots, or emanates suddenly from the earth during earthquakes and subsidence, and petrifies whatever comes into contact with it. As a matter of fact, the petrifaction of the bodies of plants and animals is not more extraordinary than the transformation of waters.

Ibn Sina, Book of Healing¹

In addition, Ibn Sina appears to have invented the concept of stratigraphy, or that the layers of rock result from depositional processes that “pile up” layer after layer through time:

It is also possible that the sea may have happened to flow little by little over the land consisting of both plain and mountain and then have ebbed away from it. It is possible that each time the land was exposed by the ebbing of the sea a layer was left, since we see that some mountains appear to have been piled up layer by layer, and it is therefore likely that the clay from which they were formed was itself at one time arranged in layers. 

Ibn Sina, Book of Healing¹

He then introduced what is now known as the Law of Superposition. Superposition states that, in stratigraphic sequences unaltered by tectonic movement, layers on the bottom of the sequence are older than layers at the top. This relatively simple idea in geology was not formally codified in Europe until 1669 by Nicolas Steno, although I challenge anyone to find a difference between Steno’s concept of Superposition and that of Ibn Sina written nearly 700 years prior:

One layer was formed first, then at a different period, a further layer was formed and piled, upon the first, and so on. 

Ibn Sina, Book of Healing¹

He even mentions possibly an unconformity, or a surface between rock layers representing “missing time” of either erosion or lack of deposition. Although instead of a gap in time, he assumes it was due to differential weathering of a different type of rock that washed away from between the rocks above and below in the same way if someone could suck out the cream filling of an Oreo cookie without pulling apart the top and bottom halves.

Over each layer there spread a substance of different material, which formed a partition between it and the next layer; but when petrifaction took place something occurred to the partition which caused it to break up and disintegrate from between the layers [translator note: possibly referring to unconformity].

Ibn Sina, Book of Healing¹

If you have read my post on “who invented paleontology,” and my posts on Shen Kuo, you may be sayin “but ahah! You wrote how these concepts were written about before Ibn Sina!” Indeed there are several references to geology and paleontology that sound quite similar to Ibn Sina in ancient Greek and Indian texts (see this post for references). And, as I have already established, Ibn Sina was a voracious reader of ancient Greek works. It therefore seems probable that Ibn Sina coopted these earlier writings to explain observed phenomena. 

However, Ibn Sina, was meticulous about citing his sources in all his other writings. He never once cited a Greek or Indian writer as the source for his geoscience ideas¹. There are also no known texts from these more ancient times that so clearly describe superposition or uniformitarianism. It does not seem very likely that Ibn Sina was using older texts to construct his ideas.¹

It is very likely that Ibn Sina invented the ideas of superposition and uniformitarianism.

The question I had after reading about Ibn Sina was, if he was so influential in medicine, why weren’t his geoscience writings also widely known? 

Geology as a science was not a in important scientific focus until the industrial era generated a need for scientists to understand, and exploit, mineral resources. Therefore, there may not have been a strong rationale for medieval scholars to pay much attention to Arabic writings about rocks.

Perhaps Europeans like Steno and Hutton read Ibn Sina and copied his ideas as their own. I hate to leave you hanging, but I’m going to wait to explore that idea more next time. (So you can wonder for a week or so if will I accuse Steno and Hutton of plagiarism.)

Ibn Sina was an extraordinary scientist whose ideas certainly influenced the world for centuries. It is time we include him as one of the true “founding fathers” of geoscience.

References

1. Al-Rawi, M. 2002. Contributions of Ibn Sina to the development of Earth Sciences. https://muslimheritage.com/ibn-sina-development-earth-sciences/.
2. Starr, F. 2015. Lost Enlightenment: Central Asia’s Golden Age from the Arab Conquest to Tamerlane. Princeton University Press
3. Wishah, G. 2018. Ibn Sina’s role in scientific discoveries. Asian Journal of Humanities and Social Studies, 6:193-200.
4. Berjak, R. 2005. Ibn-Sina – Al Biruni Correspondence: A series of correspondence containing questions from Abu Rayhan Muhammad b. Amad al-Biruni to Abu ‘Ali al-Husayn b. ‘Abd Allah ibn Sina. Centre for Islam & Science. Link