Participation is paradoxically suggested by some to curb conflicts and by others to promote their development. This introductory article, based on our reading of the literature and on the presentation of the texts collected in this issue, addresses this topic in both analytical and normative terms. One may ask not only whether institutional participatory processes have the effect of channeling or strengthening conflict but also, at a normative level, whether conflict should never be avoided or appeased and thus whether the positions that, explicitly or implicitly, support conflict against participation make sense. Beyond the opposition between the two terms, we find that it is possible to empirically observe all possible combinations of struggle and participation with very different effects, and we call for research into local debate on public projects that is able to analyze with the same care collective mobilization processes and institutional participation devices.