Is the glass half empty or half full? is a common expression, generally used
rhetorically to indicate that a particular situation could be a cause for
optimism (half full) or
pessimism (half empty), or as a general
litmus test to simply determine an individual's
worldview. The purpose of the question is to demonstrate that the situation may be
seen in different ways depending on one's
point of view and that there may be opportunity in the situation as well as trouble.