This text provides an analysis of how children come to be able to understand the dynamic nature of causality - how processes take place through time. The author studies the capabilities and limitations of 7-12 year old children in order to assess their conception of evolutionary processes. His study follows on from Piaget's work on causality, and is intended to contribute to the literature on "theory of mind" and children's scientific development. The book draws on experimental studies of diachronic thinking in children and adults, and discusses the importance of a well-developed diachronic perspective for cognition.