Imagine waking up suspended in mid‑air, with no sight, sound, touch, or memory—no sense of having a body at all.
Would you still know that you exist?
Ibn Sīnā (Avicenna) is the major system-builder of falsafa. In his metaphysics, he distinguishes between contingent beings (things that exist but could have failed to exist) and the Necessary Existent (a being that cannot not exist). Everything in the cosmos apart from this Necessary Existent is contingent; it requires a cause. An infinite regress of contingent causes would itself still be contingent. So, Avicenna argues, there must be at least one Necessary Existent whose essence just is to exist, and this is what monotheists call God. Avicenna’s famous “Flying Man” (or “Floating Man”) thought experiment targets the soul. He asks you to imagine a person created fully formed, suspended in the air, with no sensory input and no contact with their own body. Avicenna claims this person would still affirm their own existence—they would be immediately aware that “I am”—even though they would not affirm any bodily attributes. This is meant to show that the essence of the soul does not depend on bodily awareness, even if in real life soul and body are connected. Both arguments try to carve conceptual space between different kinds of dependence. Contingent things depend on causes; the Necessary Existent does not. Embodied persons in practice depend on bodies; but the essence of the soul, as a self‑aware substance, can be thought without that connection. Avicenna still wants to reconcile all this with Islam: the Necessary Existent is the God of the Qurʾan, and the soul’s survival after death fits resurrection doctrines. Reason, on his view, can climb far toward truths that revelation also teaches.
“We say: One of us must suppose that he has been created all at once and that he has been created fully developed but with his vision shrouded from seeing external things, created floating in the air or a void, such that he does not encounter any resistance or density, and his limbs are separated so that they do not meet or touch one another. Then he should consider whether he will affirm the existence of his self. He will surely affirm his self, without affirming for it length or breadth or depth, or anything else.
Thus it is clear that the affirmation of his self is distinct from the affirmation of any of his bodily parts. He is therefore aware of his self without being aware of his body.”
— Avicenna, De Anima (On the Soul) from The Healing (al‑Shifāʾ), Book I, chapter 1, standard English translation (wording approximate)
The setup is oddly vivid: fully grown, floating, no contact, no sensation. Avicenna insists that even in this extreme case, the subject would “surely affirm his self.” That “surely” is doing philosophical work—he thinks you can see by reflection that self‑awareness does not require sensory awareness. The second paragraph spells out the conclusion: awareness of self is distinct from awareness of bodily parts. You can, in thought, peel the “I am” away from any particular physical features. This does not automatically prove a Christian‑style immaterial soul, but it supports Avicenna’s broader picture: the soul is a substance whose essence is not essentially tied to any particular body. That sits nicely beside his Necessary Existent argument. Just as the chain of contingent beings points beyond itself to a being whose essence is to exist, the chain of bodily states points to a self whose awareness is not reducible to them. In both cases, he uses careful conceptual distinctions (necessary vs. contingent, essence vs. existence, self‑awareness vs. sensory awareness) as rational pathways toward religiously significant claims about God and the soul.
Think of someone using a brain‑computer interface in a full virtual environment. Their bodily sensations are rerouted; the avatar they “feel as” themself can change species, size, or even number of limbs. Yet they still report a stable sense of “I am here.” Avicenna would see this as a modern analogue of the Flying Man intuition: even when the body’s presentation shifts radically, there is a core self‑awareness that does not simply track particular sensory inputs. Debates today about whether uploading consciousness or radical neural prosthetics preserve “the same person” are, in a way, rerunning his question about what the self essentially is.
If Avicenna is right that self‑awareness does not depend on the body, does that support a dualist view of the soul, or can a physicalist say the brain alone explains this “I am”? And if reason can prove a Necessary Existent, what room is left for faith?
Quick reflection
In Avicenna’s Flying Man experiment, what exactly is the subject aware of, and how is that meant to show something about the soul?