You
Later philosophy (21st century)
The other subject that is not object (It). In Buber: the You in the I-You relation as a basic word. For us: the You as a performative presupposition of every logic --- whoever argues presupposes a conversation partner.
Origin
Martin Buber (*I and Thou*, 1923) makes the distinction I-You vs. I-It a basic theme. Levinas emphasizes the underivability of the other. For us: the You as the necessary complement of logic.