The yin and yang symbol represent the balance that is always present in the universe. Eating one piece of pizza is fine, but eating six is not a wise idea. If we have too much strength for example, this can lead to us trying to force our way upon others. We must be alert at all times to this balance or lack thereof, if we are to maintain harmony. One who learns to manage this balance, will be in a healthy state of mind, body, and spirit.