This chapter explores the nature of the relationship between topics (understood, following Leonard Ratner, as “subject[s] to be incorporated into a musical discourse”) and form. An introductory section notes the sometimes precarious disposition of topics and acknowledges the heterogeneous nature of the topical universe. This is followed by a description of the role of topics in each of the fifteen periods that make up this sonata-form movement. In addition to confirming that topics typically give profile to tonal-harmonic and phrase-structural processes, the analysis notes the relationship between topics and theme, the stylistic implications of topical usage, and the temporal character of topics.