In his extensive historical study of The Social Sources of Power (vol. i, 1986), the British sociologist Michael Mann offers a fourfold typology of types of organizational reach, a term he uses to describe the characteristics of social power networks. One dimension of the typology distinguishes between the extensive and intensive power of organizations; that is, ‘the ability to organise large numbers of people over far-flung territories in order to engage in minimally stable cooperation’ (extensive power), as against ‘the ability to organise tightly and command a high level of mobilization or commitment from the participants’ (intensive power). The other dimension of the typology distinguishes authoritative and diffused power; that is, ‘power actually willed by groups and institutions’ (including definite commands and conscious obedience), as against power which ‘spreads in a more spontaneous, unconscious, decentred way throughout a population’ (for example an understanding that certain shared social practices are natural or moral). Examples of the four forms of organizational reach thus generated include an army command structure (intensive and authoritative), militarist empire (extensive and authoritative), a general strike (intensive and diffused), and market exchange (extensive and diffused).