LitCharts assigns a color and icon to each theme in Demons, which you can use to track the themes throughout the work.
Politics and Self-Interest
Ideology and Extremism
Morality and Nihilism
Herd Mentality
Atheism vs. Belief in God
Summary
Analysis
Stepan begins drinking more and seems to be acting somewhat erratically. He hates going days without visitors. It takes Anton a while to determine what is happening, but one day Stepan looks in the mirror. He then turns to Anton and says that he (Stepan) has let himself go. Anton surmises that Stepan is struggling with his changing looks as he grows older. Until now, Stepan has nursed the conviction that Varvara finds him physically attractive in addition to being intrigued by his status as a scholar in exile. Now, Stepan worries that his looks are leaving him.
Stepan further reveals his vanity. Previously, that vanity has mostly been related to Stepan’s intellectual accomplishments (or lack thereof). Here, though, it’s clear that he is vain about his looks as well. Notably, Stepan only becomes insecure about those looks when he considers how his aging appearance will impact Varvara’s view of him, reinforcing the idea that Stepan, perhaps more than anything, wants a romantic relationship with Varvara.