This study seeks to discover the extent and manner of Debussy's use of the motive in thematic material. A total of 40 melodic examples were analyzed in order to show their relationship to a single motive, a three-note figure having a step-leap relationship. Using eighty-four series of examples, the study shows the melodies analyzed to be 85% motive-derived. The study concludes, therefore, that Images I is a remarkably economical work, using a single three-note motive as a unifying and developmental basis.