Klaus-Dieter Mathes' article "The Eighth Karmapa Mi bskyod rdo rje (1507-1554) on the Relation between Buddha Nature and its Adventitious Stains" addresses the debate over whether buddha-nature is fundamentally different from saṃsāric existence. Mathes compares the Eighth Karmapa's positions to those of Gö Lotsāwa and mainstream Jonang. Mathes argues that although the Eighth Karmapa's views changed over time, he consistently took the position that the stains are fundamentally separate from buddha-nature, and that buddha-nature is not primordially present but exists only in potentiality.
According to the Eighth Karmapa, Gö Lotsāwa depicted buddha-nature and the adventitious stains as not separate, likening the two to the ocean and waves. This is the view that buddha-nature is present in the stains; even the pollution of saṃsāric existence is pervaded with buddha-nature. Metaphors from the Tathāgatagarbhasūtra that support this position include the lotus that grows in mud and the sprout of a seed. Dölpopa argued the opposite position, that buddha-nature and the stains are fundamentally separate, like a golden statue covered in excrement, another of the Tathāgatagarbhasūtra metaphors.
The Eighth Karmapa disagreed with both of these positions. In terms of his response to Gö Lotsāwa, he argued that buddha-nature could not be of the same nature as saṃsāra because that would render the luminous nature of mind impermanent. The metaphor he used is milk mixed with water—the water acts upon the water, but the two are not the same; in other words, buddha-nature is in saṃsāra but not of it. Still, the Eighth Karmapa also disputed the Jonang position of buddha-nature being a permanently existing entity. In this section of the article Mathes carefully explains the subtle differences in the different authors' definitions of emptiness to show how the Eighth Karmapa's use of "other-emptiness" differs significantly from that of the Jonang tradition.