折疑論 1.145

1.145

客曰。聖且不了。子奚知乎（爰者何也。客反徵曰。聖人尚且不知。子何能知乎）。

The guest said, 'If even the holy did not understand, how do you know?' (Yuan means how. The guest countered by asking, 'If even holy beings did not know, how can you know?')