Philosophy
The Metaphysics of Properties: Universals versus Tropes
Quick fact
The debate between universals and tropes has been alive since Plato and Aristotle, but it remains central to contemporary metaphysics—and it directly influences how philosophers interpret scientific laws.
Why this is interesting
Why do two red apples both seem to share the same color? Is there really a single 'redness' that exists in both, or is each apple's redness a private, one-of-a-kind trait?