As editors of this fourth special Essays section of the European Journal of Theatre and Performance, we ask ourselves: what can a theatre and/or performative lens bring to the table to understand contemporary forms of activism? What can we learn from past forms and scholarship? What is the contribution of theatre and performance concepts to critical social and political inquiry, like in current debates of democracy, populism, environmentalism, violence, racism, sexism, social justice, etc.? What does it really mean ‘to act’, ‘to move’, or ‘be moved’? What is theatre’s or performance’s real (bio)power? How does theatre ‘assemble’ people or create spaces to carry on the memory of a movement in times of absence and repression? How do theatre and performance bypass censorship in support of an activism of the stage? Or do they contribute rather to a democracy that looks more like Plato’s vexed ‘theatrocracy’? And how do theatrical modes of spectating, framing, and referencing specific symbiologies come into play to incite citizens to re-act, to take part in solidarity, be it directly in the streets or more distant, in theatres or through our mobile devices?