This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Han Fei and Li Si studied together under the same teacher, the Confucian philosopher Xunzi, in what must have been one of the more consequential classrooms in Chinese history. Both men went on to become architects of the Legalist state; only one of them lived to see what it built. Han Fei, a prince of the smaller state of Han, wrote in the shadow of his own state's weakness, producing the essays that would be collected as the Han Feizi partly as an attempt to persuade his own ruler to adopt the reforms that had made neighboring Qin so formidable. Li Si left Han's ally-turned-rival and went to Qin directly, rising to become chancellor under the king who would become the First Emperor.
Han Fei's writings reached Qin before he did. The king, reportedly, read them and said he would die happy if he could only meet the man who wrote them, a compliment strong enough that when a diplomatic mission brought Han Fei to the Qin court in person around 233 BCE, the king was, by most accounts, genuinely pleased. Li Si was not. Whether from professional jealousy, a genuine judgment that a foreign prince with a family stake in a rival state could not be trusted at the Qin court, or some mixture of the two that no surviving source fully disentangles, Li Si maneuvered to have Han Fei imprisoned on suspicion of working against Qin's interests.
The end came quickly. While Han Fei sat in prison, Li Si sent him poison, and Han Fei took it, by most accounts before the king, who by then wanted to pardon him, could act. Qin went on to adopt Legalist governance in earnest under Li Si's own administration and used it to unify China within twelve years. The philosopher whose writings had supplied the clearest justification for the system did not live to see it built, killed, if the traditional account is right, by the one person who had studied that same philosophy beside him from the beginning.