The Dutchman's traits fit Mann's concept of the "Eastern" man. He is non-intellectual, mysterious, sensual, incoherent, and tyrannical. His forceful personality succeeds in regrouping the patients at the Berghof into those who are aware of the spell he casts on them and try to resist and those who surrender to him. By his mere presence, he dwarfs Settembrini and Naphta.
We discern that mere intellectual argument is futile when we see Peeperkorn together with Settembrini and Naphta. But the vaunted superiority of feeling over reason comes to naught through Mynheer's suicide. What does Mann mean? Perhaps he simply wants to demonstrate that Mynheer Peeperkorn, too, commits a fatal error: He falters because of his total commitment to emotion, for, as he admits himself, he cannot bear sacrificing intensity of emotion to the demands of everyday life.