From his pulpit, Henson spoke against the view that ecumenism was, in W E Gladstone's words, "a moral monster", and criticised schools that failed to provide adequate religious instruction. Preaching at Westminster Abbey in 1912 he attracted international attention for naming and denouncing three British directors of the Peruvian-Amazon Company for the "Putumayo atrocities" – the mass enslavement and brutal treatment of indigenous Peruvians in the company's rubber factories. During his time at St Margaret's Henson published nine books, some of them collected sermons and lectures, others on the role of Christianity in modern society and theological questions.