Is the Glass Half Full or Half Empty?

The old question of whether the glass is half full or half empty is usually taken as an indicator of whether the person who responds is an optimist or a pessimist. However, the image of that glass is taken at a particular point in time, and you really can't answer the question unless you have information from at least one more point in time. The question is a valid one and not just a trick if you know that at a prior point in time the glass had either more or less liquid in it. If the glass earlier had more liquid in it, then the glass is half empty because the liquid level went from more to less. If the glass earlier had a lower level of liquid than it now has, the glass is half full because the level went from less to more. When you make a decision, use all of the information you have, including facts from other points in time. To paraphrase Newton with a little bit of distortion, trends tend to continue unless something happens to make them change.