In Section 6, Freud examines the relationship and conflict between the dual drives of Eros and Thanatos. In the beginning, Freud questions how one might make sense of an innate drive to return to an inorganic state with simultaneous sexual instincts and a drive toward reproduction. It first appears as though the two conflicting forces may be constantly at odds with one another: Eros chasing life, while Thanatos chases death. 

However, both drives chase the same thing: immortality. Eros does this through the search for creation and reproduction. Freud references German biologist August Weisman, who developed the theory of germplasm which distinguished between germ cells and somatic cells. Freud draws on his ideas to expand his ideas about the inevitability of death and the immortality of life through reproduction.

Freud then traces the history of his evolving libido theory, which he maintains that, while incomplete, is central to psychoanalysis. He criticizes his former friend Carl Gustav Jung for defining libido as an all-encompassing psychic energy, separating it from its sexual origins. Freud argues that both the sexual libido and the pleasure principle are a part of Eros and the drive toward life.