The expressive marking "schattenhaft" appears twice in Gustav Mahler's symphonies: at the beginning of the scherzo in the Seventh and within the first movement of the Ninth. Theodor Adorno's observations regarding Mahler's use of this marking, which connect it to Schopenhauer and Romantic aesthetics, provide the framework for an examination of possible meanings of these two passages in Mahler. Drawing also on references elsewhere in Adorno's book to stylistic and formal features peculiar to Mahler's music, and especially on the comparison he makes between the experiences of reading novels and listening to Mahler's symphonies, this thesis demonstrates that close analysis of the "schattenhaft" passages offers a valuable point of entry into the thinking of both Adorno and Mahler.