Do We All Share the Same Mind? The Arabic Ideas That Shook Europe
1255: A Book That Changed Everything
In 1255, every student at the University of Paris had to read a shocking new set of books. The university made all of Aristotle’s known works mandatory, along with detailed commentaries by a Muslim thinker named Averroes (Ibn Rushd, 1126–1198). One passage in particular made jaws drop: that there is only one intellect for all human beings. What could that possibly mean? Had a whole person’s thinking power been stolen and shared out like air?
These explosive ideas didn’t come from Paris. They were carried into Europe by a wave of translations from Arabic. In the 12th century, in cities like Toledo in Spain, translators such as Gerard of Cremona (1114–1187) and Dominicus Gundisalvi (flourished late 12th century) turned a library of Arabic philosophical works into Latin. The most powerful voices in that library belonged to two giants: Avicenna (Ibn Sīnā, 980–1037) and Averroes. Their writings asked questions that would rattle the medieval world for centuries.
Did the World Have a Birthday?
Avicenna believed that God is a necessary being — a being whose very essence is to exist. Because God’s nature is unchanging, the act of creating must also be eternal. So the world, he argued, has always existed, flowing from God like light from an eternal lamp. Averroes came at the same conclusion through physics: any change in a universe that began at a moment would need a prior motion to start it, and that would lead to an infinite regress. For him, the world had no beginning.
These arguments terrified some Christian thinkers. If the world were eternal, that would challenge the Bible’s story of creation. In 1270 and 1277, the bishop of Paris, Étienne Tempier, officially condemned the eternity of the world as heretical. Still, many philosophers couldn’t ignore the logic. Thomas Aquinas (1225–1274) carefully studied the Arabic arguments and admitted that philosophically, an eternal universe seemed very probable. But faith, he said, teaches otherwise. He even wrote a treatise arguing that an eternal creation was possible — a middle path that kept the Arabic reasoning alive while protecting Christian teaching. The debate never fully disappeared.
One Mind for All? The Averroes Shock
Averroes’ most startling claim was the unicity thesis: there is only one material intellect for the entire human species. He reasoned that if the intellect were mixed with an individual body, it couldn’t grasp universal truths — like “a triangle has three sides” — that are the same for everyone. The intellect must be completely separate, a single entity shared by all, like one sun lighting many windows. Individual people think only because their personal phantasms — the sensory images stored in their brains — connect to this shared intellect.
Many Latin philosophers were both fascinated and horrified. Thomas Aquinas fired back with a famous objection: “This individual man thinks” — if the intellect belongs to nobody in particular, how can I be the one doing the thinking? He argued that such a shared intellect couldn’t explain your personal experience of reasoning.
Yet a group of thinkers called Latin Averroists adopted the unicity thesis anyway. Siger of Brabant (d. 1284) and John of Jandun (d. 1328) tried to work out how the single intellect could still act for each human without becoming an individual form. The debate peaked in the 15th and 16th centuries at the University of Padua, where championing Averroes was a badge of honour. It was only around 1550, when alternative theories of universal thinking emerged, that the attraction finally dimmed. Modern scholars still disagree about how far Averroism really spread, but the controversy over whether one mind could think for all remains one of the most vivid footnotes in the history of psychology.
What Makes You You? Essence and Existence
Avicenna gave European philosophy a tool that became legendary: the distinction between essence (what a thing is) and existence (that a thing is). He used a thought experiment: think of “horseness.” Horseness in itself is neither a particular horse trotting in a field nor the universal idea in your head. It is simply horseness — the pure definition. Only existence, which is added to essence, makes it a real, individual creature or a universal concept in the mind.
This split electrified later thinkers. Thomas Aquinas used it to explain how God can be pure existence without needing a separate essence. Giles of Rome (1243–1316) argued that essence and existence are really distinct in created things, which unleashed a long quarrel: if existence is a thing added to essence, what gives that “existence-thing” its existence? An infinite regress seemed to threaten. Duns Scotus (c. 1266–1308) carved out a different path: each individual has a “thisness” (haecceity) that contracts a common nature into a single thing, without splitting essence and existence entirely. These medieval distinctions shaped centuries of thinking about identity, reality, and how language hooks onto the world.
Why These Debates Still Matter
The big fights sparked by Avicenna and Averroes haven’t vanished. They just wear new clothes. Today, physicists debate whether time had a beginning — the Big Bang might be a moment of creation, but some models suggest an eternal multiverse. Neuroscientists ask whether consciousness can be divided, or whether a single global workspace is what lets us share meanings. When you wonder whether uploading your mind to a network would still be “you,” you’re stepping into the shadow of the Averroistic intellect debate.
Those 13th‑century students who opened forbidden books faced questions that still feel urgent: What makes a person a person? Can a truth be universal without a universal mind? The Arabic thinkers didn’t just fill library shelves — they gave Europe a new vocabulary for questioning reality itself. And the next time you feel that your own thinking belongs entirely to you, you might remember Averroes’ audacious claim that maybe, just maybe, we’re all thinking with the same piece of cosmic gear.
Think about it
- If scientists built a machine that let many brains share a single thought-stream, would each person still be a separate self? Why or why not?
- Imagine a world that has always existed without a beginning. Would life feel any different to the people living in it? What might change about their idea of meaning?
- When you describe “a cat,” you’re using a concept that fits millions of different cats. Does that concept exist somewhere outside all the individual cats and your own mind? How would Avicenna and Averroes have answered?
