 He provides the example of a computer, which using hierarchical reductionism is explained in terms of the operation of hard drives, processors, and memory, but not on the level of logic gates, or on the even simpler level of electrons in a semiconductor medium.Others argue that inappropriate use of reductionism limits our understanding of complex systems.In particular, ecologist Robert Ulanowicz says that science must develop techniques to study ways in which larger scales of organization influence smaller ones, and also ways in which feedback loops create structure at a given level, independently of details at a lower level of organization.