Three-Planes-Aligned is a lecturer at the Civic Festhall. He lectures on alignment. Players probably won't hear anything they don't already know. Of interest is what he says about "gate towns" and how they can "slide" into the planes they border on.
References[]
http://www.sorcerers.net/Games/Torment/Walkthrough/act5-findravel/findravel-festhall.php