In Black Sun, Julia Kristeva addresses the subject of melancholia, examining this phenomenon in the context of art, literature, philosophy, the history of religion and culture, and psychoanalysis. She describes the depressive as one who perceives the sense of self as a crucial pursuit and a nearly unattainable goal and explains how the love of a lost identity of attachment lies at the very core of depression's dark heart.

Kristeva analyzes Holbein's controversial 1522 painting The Body of the Dead Christ in the Tomb and makes revealing comments on the works of Marguerite Duras, Dostoyevsky, and Nerval. Black Sun takes the view that depression is a discourse with a language to be learned, rather than strictly a pathology to be treated.