This chapter examines the content and the style of the Discussion section. The Discussion section, much like the closing argument of a legal case, is the place scientific writers present an explicit argument for the meaning they inferred from the data presented in the Results section and the contribution that the research makes to the field of study. The chapter helps readers to select and organize content for the Discussion section, and write in a scientific style and edit style problems that commonly arise in the Discussion section. To the extent that science is a search for the reason that lies behind an observation, the study of rhetoric is part of the scientific tradition. The Discussion section is not the place to repeat information presented previously in the Introduction or Results sections, but to move beyond the data and background meaningfully.