Avicenna's Floating Man Predated Descartes by Six Centuries

Ibn Sina, the Persian polymath better known in the Latin West as Avicenna, wrote his Floating Man argument while locked in the fortress of Fardajan, in what is now western Iran. His patron Shams al-Dawla had died, courtiers had turned on him, and he was working out the foundations of psychology in a cell.

The thought experiment is short. Imagine a person created fully formed in midair: limbs apart, senses sealed, no contact with the body, no memory, no light, no sound. He has never seen anything, never heard a voice, never felt his own weight. Would such a person be aware that he exists?

Ibn Sina says yes. The Floating Man cannot doubt himself, even though he can doubt every limb and every external object. Self-awareness, on this argument, is not built up from sensation — it is the floor sensation rests on. From this Ibn Sina concludes that the soul is something other than the body, knowable directly and prior to anything you might learn through eyes, ears, or skin.

The move is structurally close to what René Descartes would do in 1641, when he stripped away every belief he could doubt and found the thinker still standing. Ibn Sina arrived there in the eleventh century, by way of an Aristotelian commentary tradition that had been working on the soul for a thousand years. Whether Descartes knew the Floating Man directly is debated; Latin translations of Ibn Sina's psychology had circulated in Europe since the twelfth century, so the argument was at least in the air.

The difference is that Ibn Sina was not building a method of doubt. He was after a single point about what kind of thing the soul has to be — and he made it from a cell, with the man he imagined floating outside it.