As hinted by the epigraph, the act of claiming moral neutrality in a time of crisis is the central human theme of Inferno. In Chapter 50, Sienna argues that denial is the primary foundation upon which each character’s predilection for moral neutrality stands.

Inferno argues that the twin vices of denial and moral neutrality are especially insidious as they do not normally present as conscious sins but as defense mechanisms encoded in humans to protect them against the anxieties of becoming over-conscious of the world around them. With the overpopulation issue, for instance, the sheer magnitude of the problem—and knowledge of humanity’s historical tendency to turn to prejudice, elitism, and violence to address the issue—are indecipherable enough that most of the characters outside of Zobrist and Sienna refuse to consider overpopulation an immediate issue, even when shown hard data of the severity of exponential growth.

Inferno approaches the varying reprehensibility of steadfast moral neutrality by exploring it in three characters in particular: Langdon, Sinskey, and the provost. Langdon’s denial of the overpopulation issue appears to be the most forgivable as it largely stems from his novice knowledge and relative powerlessness to solve the problem, as shown when Sienna introduces Zobrist’s theories in Chapter 50.