The appearance of the written law is the efforts that the mankind pursues the safe value of the law, and the modern code law is the attempt that the mankind pursues the safe value thoroughly. However, the history falsifies the omnipotence of the written law. 成文法的出现,是人类追求法律安全价值的努力,近代的法典法是将安全价值追求到底的尝试,历史证伪了成文法万能的思想。