"Have nothing in your house that is not useful or beautiful."
Thus spake (possibly a paraphrase) Gustav Stickley, he of the arts-and-crafts movement, that was a reaction against Victorian decorative excesses (in my view, justifiably).
Nevertheless, Gustav's pithy bromide could probably use a little editing or, perhaps, lawyering up. "Useful" is self-explanatory, I suppose and in perfect keeping with the arts-and-crafts philosophy. "Beautiful" is also fine, except, well, it's too big a loophole and therefore can lead to inconsistency with the Gustav philosophy and lots of stuff being left out on display or at least not behind glass. Beauty, of course, is in the eye of the beholder and it is entirely possible that someone could think that a room filled with useless trinkets and gewgaws was beautiful. Or worse, useful things used only for display – this would include, say, unread books that are used to simply occupy shelf space or a baby grand piano so covered in Precious Moments figurines that the keyboard cannot be accessed (In case you were wondering, the piano is the useful thing).
Now, the obvious thing is to edit the quote so that it reads "Have nothing in your home that is not useful and beautiful." While this closes the loophole, it perhaps raises the bar a bit too high and requires more than casual analysis.
Therefore, let me propose this, with all due respect to Gustav: Have nothing in your house that is not useful or meaningful.
Why "useful or meaningful"?
Because it implies that everything in the house that must be dusted or cleaned (or moved to provide access to something else that must be dusted or cleaned) is there for a reason unique to the homeowner, and that it has meaning beyond its intrinsic aesthetic qualities.
Further, it provides that your dwelling will look like you; it will reflect your interests, and not some design "vision" that has all the individuality of a hotel lobby.
It also provides a sensible ground rule when undertaking your spring cleaning: If you cannot identify what use an object is or what an object means to you, then it should go. Give it to the Salvation Army or sell it in a garage sale.