A box, empty. An empty box. Another box, Files written on the outside, containing, presumably, files - I can't say I'm interested enough to check. I'm happy - though happy is a bit strong, content rather, though even that'a a bit strong - to take it on trust, not too bothered about whether the trust is justified. What do I care if there's files in it or not? It's not my box. But anyway it's safe to assume this box does contain something, presumably files, and I remember carrying what must have been this box a distance, a short one, and it certainly did contain something, files or whatever, more than likely files; it's written on it, it means there's files inside, you don't need to check, and when those files are needed you don't need to go hunting, you just open the box and there they are, presumably.
That's what I call a box. It contains something or somethings; you open the box and there they are. But the first box, the empty one - how am I supposed to look on that? A box: something in which things are kept, carried, contained. That's a box. It shouldn't be a box otherwise. But all the empty one contains is space, and in truth that's all the box itself should be: space, that is if all it's doing is taking up space, containing space, then it would be better if it too was space, not a box. But, you will argue, it may be only half a box, so to speak, granted - a container that doesn't contain - but still, it's a kinetic box. It may some day, and almost certainly will, contain; be a box in the full sense. And, if all boxes were already boxes in the full sense, where then would we put all the stuff that needs to be put in boxes that isn't already in boxes? No, kinetic boxes are necessary, more than necessary - essential. Though come to think of it how can something be more than necessary? Essential is no more "necessary" than necessary. You need something, that's an absolute; it's necessary. You don't half need it, or kind of need it. If that's the case you need a different word, something milder, more lukewarm. You need it or you don't. Something is essential - you need it again. You don't more need it.