清代考据学以经、史为主要对象。由于考证六经、三代历史的需要，先秦诸子因其时代与大经相近而倍受重视，成为证经、证史的重要他证或旁证。或佐证事实，或校订脱讹，或旁通音训。因此，以子证经是乾嘉考据学中不可忽视的一个重要方法。

The main objects of Qianlong and Jiaqing Textual Criticism were the Confucian Classics and ancient history. Because of the Pre-Qin classics of philosophy were closely related to the Confucian Classics, they became an important reference and source of corroboration in textual research and studies on ancient history. The use of Pre-Qin classics of philosophy in textual research was an important methodology of Qianlong and Jiaqing era textual criticism.