Why is ren considered difficult to achieve in Confucian thought?

In Confucian thought, ren (humaneness or benevolence) is considered difficult to achieve because it represents the ultimate state of ethical maturity, requiring a lifelong, strenuous commitment to self-cultivation. While Confucius noted that the desire for ren is as accessible as the palm of one's hand, he simultaneously acknowledged its elusive nature, famously observing that even his most dedicated student, Yan Hui, could only sustain the virtue for three months. Confucius himself consistently refused to claim that he had attained ren, emphasizing that it is not a static achievement but a continuous process of becoming a fully realized human being.12

The difficulty lies in the requirement to move beyond self-centeredness and transform the private ego into an open self that treats others with consistent benevolence. As noted by the disciple Zengzi, the burden of ren is heavy and the road is long, lasting until death. Achieving this virtue involves a rigorous discipline of the self, the practice of filial piety, and the performance of rituals to promote social harmony, all of which demand constant effort and the ability to reform oneself when defects arise.12