This chapter describes how patients with a rare disease and their relatives view the relationships that exist or should exist between the myriad of rare disease organizations. The grouping of rare diseases into a single category raised the hope that rare disease organizations would stop competing with each other. But a specific concept of solidarity remains to be found, as patients hesitate between a “one for all” and a “every man for himself” approach. The “one for all” approach is based on the idea that progress in one rare disease will lead to progress in others, and perhaps in all diseases. The “every man for himself approach” is based on the idea that progress can only take place if each organization supports medical research and healthcare improvement for its own disease.