"They say the glass is half-full, but they don't say of what."

I'm sure everybody knows that old question 'Is the glass half-full or half-empty?'
If you answer "half-full" then you're an optimist, answer "Half-empty' and you're a pessimist. Simple really.
Unfortunately, I've always found this black/white approach a bit lacking and so I'm going to utter those four little words that will render everything I'm about to say ridiculous.

I have a theory.

It's not a wildly innovative or conspirital theory, its just a little theory that's been swirling around my head and trying to get out. So as not to risk talking to myself (which is essentially what I am doing right now), I figured I may as well place it on the internet so it won't be alone in its oddity.

I believe that to fully understand the relative capacity of the liquid inside the glass in question we must first look back into the history of the glass itself. Mainly: How did the glass get to its present half-full/half-empty state?
To my mind there are two ways this could happen-

Situation 1: An empty glass is filled from an external receptacle only up to the half-way mark. The motive behind this half-fillage is irrelevant; all that matters is that the glass has been half-filled. Thus the glass is now Half-full.

Situation 2: A full glass is emptied into an external receptacle until half the liquid has been removed from the glass. Again, motive is irrelevant and unknowable. All that matters is the fact that this glass has been half-emptied and thus the glass is *tada* Half-empty.

So really, until we can fully understand the circumstances under which the glass came to its present state of being, we cannot pass judgement upon the glass' fullness/emptiness and hence cannot use it as a measure of a person's tendency towards the positive or the negative.
Think about it.

Right, now that I've run out of conjunctions I'm off to experiment some more...
Cheerio!
C.