This post concerns the third extraordinary thinker from this period. Ibn Sina is remembered for his contributions to philosophy and medicine. His philosophical insights influenced the direction of medieval christian and jewish thought, and brought about a turning point in muslim thinking. His encyclopaedic medical textbook was the standard medical text for the next 500 years. To the non-muslim world he was known as Avicenna. He was clever and self-confident. He loved the good life and wrote about that too. He died relatively young, in his fifties. He wrote over two hundred books, of which about a quarter have survived and some are still in print. Amazon has an Avicenna author page.
Here is the cover of a latin translation of Ibn Sina’s Canon of Medicine, printed in Venice in 1520. Courtesy Muslim Heritage
Unlike his contemporaries, al-Biruni and ibn al-Haytham, quite a lot is known about him. He was born near Bukhara, in what is now Uzbekhistan. At the time it was one of the most vibrant cities in the world, experiencing the flowering of Persian culture in the muslim golden age. Because of the political turbulence of the times he also had to move a lot, but that didn’t seem to cramp his style.
For me, his greatest contribution was his utter belief and confidence in the human faculty to make sense of the world we live in. He described himself as self-taught, but my suspicion is that the assertion was more to make a point than describe his own education. Especially as he referred to teachers elsewhere in his writings. However, he believed that the human does not need to resort to inexplicable outside agencies in order to understand all we perceive. In proposing this he challenged both popular culture (this was the world of the Thousand and One Nights with its stories of djinns in bottles and enchanters who could turn people into animals with their magic powers) and the established religion of islam, of which he was an adherent.
In the schools of philosophy at this time, Aristotle was the reference point. Ibn Sina updated Aristotle. He proposed a distinction between the seen and the unseen, which he described as essence and existence. He demonstrated that the two are distinct by the device of thought experiment. His ‘floating man’ thought experiment imagines a person with no sensory input at all. They can’t see, hear, smell, taste or feel anything. And yet, that person will still be self-aware even without any external confirmation that they exist. He described the part that knows this as the soul, the essence of the person.
He put forward a rational proof of the existence of God, working from first principles. Everything we see around us, from a blade of grass to a star in the heavens, owes its existence to something else. Its existence is not independent but contingent on something else. Just as you and I could not have come into existence if our parents had not got together, and they could not have appeared without the existence of our grandparents, so everything goes back and back. Where does it stop? There has to be an originating cause, which is not contingent on anything else. He called this the ‘Necessary Existent’ .
What impresses me about this approach is not whether or not it was right, but the fact that he dared to try.
He then went on to demonstrate, by means of reason alone, that there can only be one necessary existent. The reasoning goes like this: If there were two, they would either be identical (in which case they would effectively be the same thing) or different. If different, what is the distinguishing quality? Is one larger than the other? Are they in different places? Our understanding of the two so-called necessary existent things then becomes contingent on that quality that makes them different. And so we have to go back further in order to find the necessary existent.
These conclusions conveniently coincided with the tenets of islam, that there is one God. Ibn Sina’s way of working influenced Moses Maimonides, the medieval Jewish philosopher and Thomas Aquinas in latin Europe. A few generations later, al-Ghazali had Ibn Sina in his sights when he wrote ‘The Incoherence of the Philosophers’.
For me, Ibn Sina, al-Biruni and Ibn al-Haytham won something for us all. They won us the permission to trust in our own ability to understand the world we live in. I thank them for that.