摩訶止觀 5.235

5.235

若前念不滅後念生：此則念自生念，兩生相並，亦無能所。若前念有生性，生於後念，此性為有？為無？有則非性；無則不生如前。

If the subsequent thought arises when the prior thought has not ceased: this would mean a thought gives rise to a thought from itself, so two arisings would exist side by side, lacking agent and object. If the prior thought possesses the nature of arising and produces the subsequent thought, does this nature exist or does it not exist? If it exists, it is not a nature; if it does not exist, it does not arise, as refuted before.