Rowan Williams explores the major and timely idea of solidarity in this impassioned work. Solidarity is both an idea and a way of acting in in the world, both a condition and a virtue. From its use in the labour movement as a rallying cry to stand shoulder-to-shoulder against a common enemy to the rhetoric of empathy, allyship and identification prevalent on contemporary social media, 'solidarity' is invoked as the answer to inequality, conflict and even climate crisis. But, as Rowan Williams argues in this impassioned work, it's only by exploring how we are able to speak with and work alongside each other that we can unlock the real power of solidarity as a model for real community and care. Tracing the myriad of ways in which solidarity has been understood, from its roots in the French Revolution, through the positivism of August Comté and Emile Durkheim, to resistance against the Nazis and Communism, Polish workers' rights movements and the Nueva Solidatyridad in Mexico City, Williams shows how understanding solidarity is an ongoing labour of self-scrutiny and communication in which difference and strangeness are affirmed, not elided. This insistence that solidarity requires recognition - in the deepest sense - is an impassioned one; true recognition is not claiming they are 'just like us' but joining with their claim that they 'are themselves'. And it is in this recognition, one which is also capable of encompassing the non-human, that true hope for the future can be found.