Mechanism, Organism, and Society: Some Models in Natural and Social Science

1. Models,, Knowledge and Structure. Men think in terms of models. Their sense organs abstract the events which touch them; their memories store traces of these events as coded symbols; and they may recall them according to patterns which they learned earlier, or recombine them in patterns that are new. In all this, we may think of our thought as consisting of symbols which are put in relations or sequences according to operating rules. Both symbols and operating rules are acquired, in part directly from interaction with the outside world, and in part from elaboration of this material through internal recombination. Together, a set of symbols and a set of rules may constitute what we may call a calculus, a logic, a game or a model. Whatever we call it, it will have some structure, i.e., some pattern of distribution of relative discontinuities, and some "laws" of operation. If this pattern and these laws resemble, to any relevant extent, any particular situation or class of situations in the outside world, then, to that extent, these outside situations can be "understood", i.e., predicted-and perhaps even controlled-with the aid of this model. Whether any such resemblance exists cannot be discovered from the model, but only from a physical process of verification, that is, physical operations for matching some of the structure of the outside situation-this we might call "taking information off" the outside situationfollowed by some critical process, i.e., further physical operations which depend in their outcome on the degree of correspondence between the structure proposed from the model and the structure derived from the outside facts. Models of this kind may unify the thinking of their users. If clearly retained, they make mental operations repeatable: they confer on them the property of retraceability which is essential for reason. If used by several persons with identical results they add another characteristic of reason: cogency. They will do this whether their actual correspondence to events in nature is close or not. In one sense, all these models are physical. They consist of symbols which are states of physical objects, and traces of physical processes, whether in brain cells, ink marks, electric charges, or what not. Similarly, the operating rules, according to which these symbols are to be permutated or combined, and new symbols derived from them, are constraints on physical processes. In this sense, knowledge is physical process, or rather a particular configuration of physical processes. It is the process in which at least three other physical processes are incompletely matched: one, the "outside" process, which undergoes