Is the glass half full or half empty? Psychologists will tell us that how a person describes that glass of water can tell you a good deal about a person. The person who sees the glass as half full generally is more positive and optimistic. Conversely, the person who views the glass of water as half empty generally is more negative and pessimistic.
I was thinking about the positive/optimistic versus the negative/pessimistic viewpoints in terms of the principle of reciprocity (i.e., The Golden Rule).
Whether a person subscribes to the faith of Christianity or not, my bet is that most people are familiar with the line attributed to Jesus in Luke 6:31 that we generally phrase as Do unto others as you would want them to do unto you. From the standpoint of the glass analogy, this statement falls within the positive/optimistic spectrum.
Outside of Asian circles, few westerners are aware that Confucius stated much the same thing centuries earlier. However, in the Confucian formulation, the statement is more akin to the half empty glass. In the Analects 15:23, the Master says, "What you do not want done to yourself, do not do to others."
It can certainly be argued that, regardless of the direction of these two statements, the sentiment is much the same. In my mind's eye, however, I think the Confucian version is more forceful and would lead most of us to live more virtuous and ethical lives.
I base this supposition on my own observations of human nature. Most of us, whether we care to admit it or not, go through life formulating cost-benefit analyses of every situation. How can I give as little as possible to get the most back? When this formulation is paired with the version of The Golden Rule attributed to Jesus, we try to figure out the bare minimum of how to treat others to have the full measure reciprocated.
For example, if we desire for others to worship at our feet, we try to calculate the smallest amount of kindness or compassion to show others in order to convince them to grovel before us!! In other words, while we might follow the letter of the law, we don't tend to follow it in spirit.
But, when we turn this notion around to gaze at it from the Confucian angle, we are far more likely to err on the liberal side of the equation. If we don't want others to beat us about the head, we will go out of our way NOT to beat them on their head, shoulders or upper torso. In order NOT to receive that which we don't want, we set the stage by NOT doing to others on the scale of two or threefold what we don't want to receive back.
So, while it could be argued that the Confucian precept is more negative, in tone, I would argue that it is more positive in outcome. By seeing the glass half empty, it turns into the glass half full.