Philosophy
The Metaphysics of Composition and the Special Composition Question
Quick fact
Peter van Inwagen introduced the Special Composition Question in his 1990 book Material Beings, and he famously argued that the only things that compose a further object are those that constitute a life, making living organisms the only composite objects.
Why this is interesting
You are looking at a table, but is the table really there—or is it just a convenient way to talk about millions of particles? When does a pile of parts become a single thing?