In this, Simon contrasts with the more recent work on democratic governance of his once-collaborator James March. See March and Olsen (1995). Simon discussed his political activities, and his brush with Cold War blacklisting, in his autobiography (1991: 117-134).
 See Newell, Shaw, and Simon (1960); Newell and Simon (1963); Newell and Simon (1972).
 Edwards (1996: 250) rightly emphasizes this point.
 The argument of "The Architecture of Complexity" also appeared in a more compressed form in Simon (1960: 40-43). Administrative Behavior includes a concept of "hierarchy of authority", but the concept of hierarchical structure is not central to the argument. In a late paper with Mie Augier meant to serve as an introduction to "The Architecture of Complexity", Simon extends his arguments in the light of more recent computational models of evolution (Augier and Simon in press). I am indebted to Mie Augier for sending me a prepublication copy of this paper.
 For example, it is useful to contrast Simon's conception of structure with the autopoietic theory of Maturana and Varela (1980). Elsewhere in his 1968 lectures, Simon (1969: 24-25; cf. Agre 1997: 56) presents his famous parable of the ant whose complex path along a beach is determined jointly by the ant and the beach. Many authors have presented this as evidence of the interactionist nature of Simon's theory. Yet Simon announces a page later that he is only interested in cognition and not in embodied activity. The point of the ant story is that a general problem-solving mechanisms enters into unpredictable interactions with an abstract problem space -- a formal construct with no necessary relationship to the physical or social environment. On the other hand, it should be noted that Simon himself was certainly familiar with servomechanism models and had published a number of papers that employed them; see, for example, Simon (1952). In his autobiography (1991: 108-109) he credits his use of control theory to the influence of his father, an engineer.
 He also acknowledges (1969: 94) that not all structures are hierarchical, giving the example of polymers, which are long chains of identical units. "However", he says, "for present purposes we can simply regard such a structure as a hierarchy with a span of one -- the limiting case".
 The "span" of a hierarchy is the number of subordinates beneath each element.
 Dawkins (1986) later played with this image when he referred to evolution as "the blind watchmaker". For the subsequent history of evolutionary metaphors in economic studies of organization see Nelson and Winter (1982) and Hodgson (1993, 1999). On evolutionary metaphors in the development of technology see Basalla (1988).
 On the long Western tradition of likening the engineer to God, see Noble (1997). On the clockwork metaphor see McReynolds (1980).
 To be sure, Margulis (1998) has subsequently argued that the cell's internal structure arose through the symbiotic combination of formerly independent organisms. In this case Simon's theory does apply.
 Poerksen (1995) argues that bureaucratically rationalized language is increasingly composed of modular elements that lack the embedding in community and history that normally gives language its fullness of meaning. Yet Blair (1988) argues that an affinity for modularity is a central feature of American culture.
 On the role of modularity in industrial design and strategy, see Baldwin and Clark (2000), Economides and Salop (1992), Langlois and Robertson (1992), Meyer and Lehnerd (1997), and Schilling (2000).
 Simon (1969: 89-90) makes clear that hierarchies are defined in terms of interaction patterns, not spatial proximity. The point here is that the metaphor of hierarchy as a physical structure is spatial.
 For numerous additional criticisms of the association between evolution and efficiency, and in particular the inference that hierarchical firms are efficient given their mere existence, see Hodgson (1991).
 On the subsequent history of metaphors of self-organization in the social sciences, see Contractor (1999).
 See Vera and Simon (1993) and Agre (1993; 1995; 1997: 54-57, 142-143).