Mozi, named Di, was a great thinker of the Warring States period and the founder of the Mohist school. He advocated "universal love" and opposed war.
Around the same time as Mozi, there was a philosopher named Yang Zhu who opposed Mozi's "universal love," advocating for "valuing life" and "self-importance," emphasizing the preservation of personal life and opposing both others' encroachment on oneself and one's own encroachment on others.
Once, Mozi's disciple Qin Guli asked Yang Zhu, "If plucking a single hair from your body could benefit all the world, would you do it?" Yang Zhu replied, "The world's problems cannot be solved by plucking a single hair!" Qin Guli pressed, "If it were possible, would you be willing?" Yang Zhu remained silent.
Mencius, the great Confucian thinker, once contrasted the two philosophers Yang Zhu and Mozi, saying, "Yang Zhu advocates for the self—even if plucking a single hair from his body could benefit the entire world, he would refuse. But Mozi preaches universal love—if it could help all people, he would gladly wear his head bald and his feet calloused from toil."
Later, the idiom "Not Even One Hair" came to describe extreme stinginess and selfishness.
Source: *Mencius*, Chapter "Jin Xin"
Meaning of the Idiom: Later, the Chinese idiom "一毛不拔" came to describe extreme stinginess and selfishness.