Monistic anthropologies were very popular around 1900. Contrary to the Platonic-Christian tradition, many intellectuals at the turn of the century no longer defined man as a duality of body and mind, but conceived of him as a transcendence-free 'body entirely'. This study elaborates on the anti-dualistic commonalities in philosophy, psychology and medicine around 1900, but also discusses the problems intellectuals became entangled in with their decision for immanence. In a second step, the study shows that a particular sensitivity for the problems of monism was developed in the medium of literature around 1900. Within the framework of differentiated individual studies on texts by Hugo von Hofmannsthal, Robert Musil, and Thomas Mann, the literary paradigm of an aporetic modernity differing from a bodily modernity by a decidedly poetic skepticism is thrown into relief.