Manuscript, novel, book, atom, force, and network are all "things."

Not all things are concrete objects. Some are physical objects but whose existence we can only infer as they are too large or small to see, some are descriptions of classes of physical objects, some are concepts, some are abstractions, but all are things. We give names to imaginary constructs, too: isn't Cerberus, the mythical three-headed dog, a thing?

"Animal, vegetable, or mineral?" does not encompass every thing, let alone everything. Many years ago my college rooming group stumbled during a game of "Twenty Questions" when someone used "pitfalls" as the unknown and couldn't assign it to an acceptable category...


"Nothing" is another problem altogether. Often it's confused with "zero" and with "no thing," and the potential for linguistic ambiguity has given rise to all kinds of apparent paradoxes and amusements(*). Quite a diverse spectrum for a profound concept - "All null sets are the same" is the basis of the entire number system.

(*)For example: no horse has four tails. One horse has one more tail than no horse. Therefore - one horse has five tails. Q.E.D.!