If I say that all faces are beautiful, the word "beautiful" is meaningless, because, as far as I can see, it only has meaning if something can be "ugly". Now what if I say that all music is perfect, does that make sense? I think not, but it's not as obvious why not. What if I say that all days are cold, does that make sense? It might, if there was some kind of independent standard of coldness, which all days complied with. I'm looking for some kind of rule which tells me what kind of sentences of the form all X is Y are meaningless and what kind of sentences are not. Is there a rule? Thank you.