Originally posted by The Wizard of Oz
Actually, that reminds me of something else I've wondered.
We always assumed that Spirit-Detecting Glance lets you see and hear spirits. So you could have a conversation with a dematerialised spirit without them having to appear (either in solid or in intangible form).
But it does just say it lets you "see" spirits, so maybe that's wrong?
I see no reason to disallow conversation, so go for it.