Ibn Sina · Theology
Ibn Sina’s elegant proof that, beneath all the contingent things that might not have existed, there must be one Necessary Existent that cannot not exist.
Ibn Sina - Avicenna to the Latin West - was the most influential philosopher of the Islamic golden age, and he devised one of the most elegant arguments for God ever made. Earlier proofs reasoned from motion or from creation in time. Ibn Sina reasoned from existence itself - from the bare fact that anything exists at all. He so prized this proof that he called it the burhan al-siddiqin, the ‘Demonstration of the Truthful,’ because it begins not from the world’s features but from existence as such.
Here is the heart of the argument. Every contingent thing depends on a cause for its existence. That cause, if also contingent, depends on a further cause, and so on. Now consider the whole collection of contingent things, the entire chain. The collection is itself contingent (a totality of dependent things is dependent), so it too requires a cause for its existence - and that cause cannot be within the collection (nothing causes itself) nor another contingent thing (that would be inside the collection). Therefore the cause of the whole contingent order must be something non-contingent - a Necessary Existent, existing by its own nature, on which all contingent existence depends.
Beneath the proof lies Ibn Sina’s most original idea: in every contingent thing, essence (what it is) and existence (that it is) are distinct. You can fully grasp what a phoenix or a triangle is without knowing whether it exists; existence is not contained in the essence, but ‘added’ to it. So a contingent thing’s existence must come from outside, from a cause. Only in the Necessary Existent are essence and existence identical: its very nature is to exist; existence belongs to it not as something added but as what it is. This distinction - essence versus existence - is the metaphysical engine of the whole proof, and one of the most consequential ideas in the history of philosophy.
This is the opening of the lesson. The rest — the dialogue, the primary source, and the recall — is in the app.
You learned that Ibn Sina divides all things into contingent and necessary and argues a Necessary Existent must exist. Reconstruct his reasoning, and the main objection to it, in your own words.
Leads to Thomas Aquinas.
Begin this lesson →epoché — a humanities education that remembers you.