Thinking skills’ is a term that has been substantially over-used. It often seems to be rather a lazy shorthand for justifying the teaching of history by suddenly bolting on some ‘thinking’ - as if history is not all about thought in the first place. Arthur Chapman suggests using techniques from his critical thinking teaching in the history classroom to clarify students’ thinking about the processes involved in forming historical interpretations. Specifically, he suggests techniques for improving students’ thinking about the assumptions which underlie any argument. He provides examples which are very ancient and very modern: the grave found in the West Country which might have been that of the ‘King of Stonehenge’ - or the ‘Amesbury Archer,’ according to the press, but seems more likely to have originated in another country entirely; and the assumption that German society in the 1930s was terrorised by the secret police. Chapman is the man who recently brought us Alphonse the Camel (whose back was broken by the final straw) to help us to think about causation. Now he adds to the menagerie with an ass and a polar bear to investigate the power, and the danger, of assumption.