It seems what happened is that all the promising/useful areas of inquiry from ancient philosophy have since become their own fields. "Natural philosophy" became

It seems what happened is that all the promising/useful areas of inquiry from ancient philosophy have since become their own fields. "Natural philosophy" became physics/biology/chemistry and so forth. Thus university philosophy departments were basically left with the dregs -- lots of debates over non-falsifiable claims, lots of debates caused by poor definitions of words. Ethics is the only subfield of modern philosophy I can think of that seems useful and interesting to me. Maybe political philosophy too, but that has mainly moved to the political science department.