Ritschl’s advice to Harnack is reported to have been something like this: ‘Never mind about the politics—get on with writing the books that will change the way people think. In the long term, that is what will be of decisive importance.’ As one looks at the sustained gains made by liberalism in German Protestantism up to the eve of the First World War, the wisdom of Ritschl’s advice is clear. To win the long-term victories, you have to influence the way in which a rising generation thinks. But why