Things and Stuff

From my book Carmine Vermilion (an underground train of thought):

A thing is solely comprised of its own borders. Stuff can be comprised of anything. Actually, the correct wording is that every limit case that a thing is part of is incident to a limit case being part of the thing. So mathematically, the relations that a thing has with the outside world are perpendicular, oblique, tangential or identical but they are always incident. Whereas stuff can have every relation. Said correctly, there is always a limit case that stuff is part of which is not incident to any limit cases being part of the stuff. Stuff may still have all the incident relations, but it never satisfies the definition of a thing, however close it comes. Note,” he smiled as he pinched her, “that this still leaves room for stuff to be in things and for things to be in stuff.”