Some Analogies of Hierarchical Order in Biology and Linguistics*

The ubiquity of hierarchical order is obvious, and the obvious is hard to explain, but a number of workers [1] have suggested the possibility of constructing a theory (or cluster of theories), rooted in such disciplines as thermodynamics, information theory, topology, and logic, which might reveal the underlying unity of a wide variety of branching and multi-level systems. It is the purpose of this paper to contribute to both the empirical and theoretical aspects of this discussion, by examining levels of structure and function in molecular biology and linguistics, and by developing, from parallelisms between these two areas, a hierarchical model of possibly greater generality.