With regard to repetition compulsion, analysts tend to have opinions ranging from the extreme of regarding it as a functional mechanism to that of viewing it as a primary, irreducible need. Hollande and Soulé set before the colloquium the task of answering the questions: who repeats; what does the patient in analysis repeat; how does the ego use this drive, which appears most often as bound energy? In suggesting approaches to the answers to these questions, the authors survey theoretical and clinical studies, biological genetics, and ethology.