The Forum

Acts of defiance small or large have proved to be incredibly powerful throughout history, but when does defiance spill into aggression? Bridget Kendall asks the employment lawyer Lewis Maltby, the theatre director Olivier Py and the psychopathologist Dr Luna Muñoz Centifanti. (Photo: Historic Marker at the bus stop in Alabama, USA, where Rosa Parks refused to give up her seat. Credit: Getty Images)