In Difference and Repetition, Deleuze claims that it is in virtue of a relation of expression which holds between intensive processes of individuation and virtual Ideas that the former determines the latter to be actualised in concrete entities. He is, however, less than forthcoming in this book about exactly how we should understand the relation of expression. This article addresses itself to this lacuna. It clarifies five characteristic features of the expressive relation, partly by drawing on Deleuze's discussion of the (...) relation of expression in Expressionism in Philosophy, party by examining familiar examples of expressive relations. It then maps these characteristic features of expression onto Deleuze's discussion of the relation between Ideas and intensity in Difference and Repetition, showing that virtual Ideas are ontologically inseparable from the intensive processes that both constitute and actualise them in the production of actual entities. By way of conclusion, this expressive account of the relation between the virtual, the actual and the intensive will be compared and contrasted with several leading accounts to be found in the secondary literature. (shrink)