/sigh

The glass is half-empty if you are in the process of decreasing the amount of liquid in the glass. It is half-full if you are in the process of filling the glass. Thus the last action that you took - whether filling or emptying the glass - determines which term to use. If you have an empty glass and fill it to the middle, it is half-full because the last thing you did was fill the glass. It would make no sense to call something half-empty, and thereby giving it an emptiness quality trait, when in actuality its existence as a glass with water at the middle point was brought forth by filling it, and not emptying it. If a glass has liquid at approximately the half-way point and someone takes a tiny sip of it, it is being emptied, and thus is half-empty. If someone adds a tiny drop of water to it instead, it is considered half-full, since it is in the process of being filled.

Once again, saying a glass is half-empty after filling it with something is both illogical and nonsense. The liquid inside of the glass exists based on two actions - emptying and filling. The action which has most recently taken place takes precedence in arriving to a conclusion. Therefore the real question is in what way was the liquid inside of the glass altered last, was it emptied or filled? If someone asks whether the glass is half-full or half-empty, ask them in what way it was altered last. If they don't know, then ask for the five seconds of your life back. If they said they had consumed half of it, then say it is half-empty. When they say that means you're a depressed person, slap them.