 These examples point to a ubiquitous but elusive conceptual distinction between stuff and things. Paradigmatic examples of stuffs are wood, water, hydrogen, and iron. Less paradigmatic stuffs include beer, salsa, and butter. The most general physical stuff-kind is matter. The concept of stuff is even more general than matter. Concepts such as ectoplasm, justification, or phlogiston may refer to spiritual or abstract stuff. ‘Things’ or ‘objects’ refer, most paradigmatically, to medium-sized entities such as tables and cables, pears and bears, and rocks and socks.