Thematic unity in music occurs when elements from a musical idea appear frequently, in significant places and their presence is recognized or experienced on or beneath the surface. In fugal compositions, thematic unity is evident in the opening statement of the subject and it permeates each layer of its texture. Three analytical perspectives are used to investigate the degree to which local thematic material anticipates later structural features in Johan Sebastian Bach's Fugue in G minor WTC II, and Georg Frederic Handel's Fuga II in G Major. The analytical perspectives identify: (1) cohesive relationships between motivic fragments, (2) underlying motives and their relationships to keys and harmonic progressions, and (3) voice leading reductions relative to linear and tonal prolongation. Arnold Schoenberg, Hans Keller, and Rudolph Reti provide valuable insights concerning the organic nature of thematic material. The voice leading reductions of Heinrich Schenker and William Renwick offer procedures that reveal underlying thematic relationships. The cohesive elements of the selected fugues will be explained with reference to immediate and long-range relationships.