Mencius observed that humans depend on one more important mental function. He called it the 志 Zhì, which can sometimes be translated as "aspirations," but which in the case of Mencius is what we would call the will. Something has to decide what to do when the ethical impulses, the moral feelings, of what Mencius called the "four virtues," conflict with the ordinary impulses that are involved with hunger, sex, aggression, fear, etc. The part of humans that balances things and makes decisions is the zhì.