This month marks the anniversary of the global protests following Donald Trump’s inauguration as US president. The Women’s March on Washington and its sister events brought millions of people together and was, for many participants, an extraordinary, all-too-rare moment of collective pleasure.

“Sometimes, the strength we gain from moments of joyful solidarity lasts a very long time,” writes Lynne Segal towards the end of Radical Happiness: Moments of Collective Joy, which unpicks what she acknowledges is the “intangible” notion of joy. Segal’s thesis is that in losing one’s sense of self and self-consciousness, becoming part of bigger political and societal movements, one can achieve both personal joy and hopeful belief in the possibility of changing the world. Subsequent events in 2017, such as the #MeToo movement, suggest that she has a good point.

Segal, a professor of psychology and gender studies at Birkbeck College, London, recounts her own experience as a leftwing feminist and activist to back up her wider point about the power of mass movements — which in this book means gatherings of real people. Little space is devoted to social media-driven activism. It feels like an omission but she is perhaps right: young feminist activist thinkers such as Zeynep Tufekci are better placed to offer techno-sociological analysis.