'Triggering'. When and where did the usage originate? No one is sure. There is, however, clear connection with the psychiatric term 'trauma trigger' - stimuli which can detonate unhealed wounds. The concept of triggering took off in feminist magazines and social media 'chat' around 2010. Around 2013/14 it moved, wholesale, into higher education. In May 2014, the New York Times reported that at scores of institutions student bodies were demanding trigger warnings in their courses for canonical texts. It reached a floodmark with a survey by The Times of London in August 2022 which found that British universities had covertly added trigger warnings to over a thousand texts, including the works of literary greats such as Geoffrey Chaucer, William Shakespeare, Jane Austen, Charlotte Brontë, Charles Dickens and Agatha Christie. Politicians in the US, UK and Australia vilifies triggering with the sarcasms 'wokery' and 'snowflakery'. What is overlooked in the heat of the argument is that triggering is categorically different from traditional institutional controls on literature. Triggering, done responsibly, honours the fact that great literature is great because it is, as Kafka says, powerful. In this extraordinary polemic, John Sutherland - former Visiting Professor of Literature at the California Institute of Technology - takes a wide-ranging and characteristically nuanced look at the history of triggering and censorship in literature and shows how it has become a theatre of culture warfare. Politicians in the great sectors of the English-speaking world have taken up arms in that conflict. Jonathan Swift's 'Battle of the Books' has flared up again.