In addition, some scholars such as Kazuo YANASE pointed out that 'the 7th volume and the 8th volume might have been added by other person,' because in a same rufu-bon the writer's thoughts expressed in the 1st - 6th volumes are different from those of the 7th and 8th volumes.
なお梁瀬一雄など一部の研究者からは、流布本の巻一～六と巻七・八では背景となる思想などが異なるとして「流布本の巻七・八は別人による増補ではないか」との指摘がされている。