This chapter reviews the received view about emergence (to the extent that there is such a view). It argues that for at least some forms of emergence the important feature is the asymptotic nature of the relationship between the emergent properties and the lower level characterizing the components. It also argues that contrary to the received view, there can be emergent properties in situations in which there are no part/whole relationships. The example of the rainbow is discussed further in this context.
Keywords: causal powers, emergence, mereology, parts, rainbow, reduction, thermodynamics, wholes