'Isn't the trigger the thing that sets the rest of it on fire?'

Analogies for teaching about causation abound. Rick Rogers is alert, however, to the risks inherent in drawing on everyday ideas to explain historical processes.

What most often gets lost is the importance of the chronological dimension; both the length of time during which some contributory causes may have been present, and the ways in which they change over time, which have an impact on the interplay between them. In response to this problem he offers a causation map - a visual device intended to give children a sense of scale and of the fluctuations within individual causes. The idea is obviously widely applicable and immensely versatile, with scope for such maps to be used at many different stages of a causation enquiry; to be generated by teachers or students; and to be designed to reveal or reflect different interpretations...