Explain that Mencius is wrong when he thinks that men are born good. Tzu believes that Mencius' statement shows that he does not understand the difference between fundamental nature and conscious activity. Nature is described as what is given to you from Heaven and is something you cannot learn. Ritual principles, however, are factors you can learn and work on until they are perfected. Those factors that you cannot learn are considered nature while those that you can learn are conscious activity. An example of this is that men are given the luxury of sight and hearing. Clear vision and fine hearing cannot exist without eyes and ears. These are not factors acquired from one man's studies. This shows that there is a difference between nature and conscious activity. Mencius emphasizes that men are good and become evil only when they lose their original nature. Tzu contrasts this opinion with his own, saying that men move away from simplicity and naivety the day they are born. This shift means that men have lost their original nature. The loss of man's original nature the day he is born proves that men are natural