A catchphrase of general system theory and related approaches intended as an antidote to radical or ‘greedy’ reductionism. It conveys the message that the behavior of complex systems cannot be explained from an analysis of its individual components. Rather, it is the interactions or relationships between the components that gives rise to the emergence of properties not found in any of the components individually. Some have argued that the catchphrase should be re-phrased to “whole is less than the sum of its parts”, as what emerges is a unification of the behavior of disparate parts.
See Emergence, General system theory, Gestalt good form, Holism, Reductionism, Self-organization