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One set is inputs: the currents flowing through them reflect the parameters of
the factory (orders, stocks, cash-flow, etc.). The other set is outputs: the volt-
ages they detect represent instructions to the factory (buy more raw materi-
als, redirect production flows). There will be some determinate relationship
between these inputs and outputs, fixed by the current thread structure, but
this structure will itself evolve in practice in a process of reciprocal vetoing, as
Beer callled it, and, as Ashby would have said, the combined system of factory
plus controller will inevitably “run to equilibrium.” Like a set of interacting
homeostats, the chemical computer and the factory will eventually find some
operating condition in which both remain stable: the factory settles down
as a viable system, in Beer's terms, and the chemical computer, too, settles
down into a state of dynamic equilibrium (at least until some uncontrollable
perturbation arrives and disturbs the equilibrium, when the search process
starts again).
The magic is done—well, almost. Pask thought through at least two fur-
ther complications. First, there is the question of how to get the process of
coupling the computer to the factory going. One answer was to envisage a
“catalyst,” a system that would send current through the “least visited” elec-
trodes, thus fostering a variety of interactions with the factory and enabling
the computer to interrogate the factory's performance on a broad front. Of
course, second, the procedure of simply letting the computer and the fac-
tory search open-endedly for a mutual equilibrium would almost certainly
be disastrous. Who knows what terminally idiotic instructions the computer
would issue before stability was approached? Pask therefore imagined that the
manager would be allowed to
train
the controller before he retired, monitor-
ing the state of the factory and the machine's responses to that and approving
or disapproving those responses by injecting pulses of current as appropriate
to reinforce positive tendencies in the machine's evolution, as indicated in
figure 7.13. Pask noted that this kind of training would not take the form of the
manager dominating the controller and dictating its performance; there was
no way that could be done. In fact, and as usual, the interaction would have to
take the form of a “partly competitive and partly collaborative game” or con-
versation (Pask 1958, 170): “After an interval, the structured regions [in the
controller] will produce a pattern of behaviour which the manager accepts,
not necessarily one he would have approved of initially, but one he accepts as
a compromise.” Thus the manager and the controller come into homeostatic
equilibrium at the same time, in the same way, and in the same process as the
controller comes into equilibrium with the factory. “At this point the struc-
tured region will replicate indefinitely so that its replica produces the same
