肇論新疏 1.245

1.245

性莫之易，故雖無而有；物莫之逆，故雖有而無。雖有而無，所謂非有；雖無而有，所謂非無。

"Because their nature does not change, although non-existent, they exist; because things do not oppose it, although existent, they are non-existent. Although existent, they are non-existent, which is what is called 'not existent'; although non-existent, they exist, which is what is called 'not non-existent.'"