The authors outline some of the ways in which they teach student teachers to think about the challenges of abstract concepts in science. They ask the student teachers to think about abstract ideas in a non-science context first, and find they are enabled to discuss and engage (and then later apply) their thinking better. The authors think that there is a need to be realistic in terms of how people conceptualise abstract thoughts and ideas and to be honest about those that can be simply accepted without question because one cannot actually comprehend them.