ROSS ASHBY - The Cybernetic Brain - page 98

1941, but it was not until 1948 that the Homeostat was built to embody the
special process. . . . Since then he has worked to make the theory of brainlike
mechanisms clearer” (Ashby 1962, 452). I will not try to trace out the evolu-
tion of his thinking from 1928 onward; instead, I want to pick up the historical
story with Ashby's first protocybernetic publication. As I said, Ashby's clinical
concerns are very much marginalized in his key cybernetic works, which fo-
cus on the normal rather than the pathological brain, but we can explore the
interconnections later.
Ashby's first step in translating his hobbyist concerns into public discourse
was a 1940 essay entitled “Adaptiveness and Equilibrium” published in the
Journal of Mental Science . In a journal normally devoted to reports of mental
illness and therapies, this paper introduced in very general terms a dynamic
notion of equilibrium drawn from physics and engineering. A cube lying on
one of its faces, to mention Ashby's simplest example, is in a state of dynamic
equilibrium inasmuch as if one tilts it, it will fall back to its initial position.
Likewise, Ashby noted, if the temperature of a chicken incubator is perturbed,
its thermostat will tend to return it to its desired value. In both cases, any
disturbance from the equilibrium position calls forth opposing forces that re-
store the system to its initial state. One can thus say that these systems are
able to adapt to fluctuations in their environment, in the sense of being able
to cope with them, whatever they turn out to be. Much elaborated, this notion
of adaptation ran through all of Ashby's later work on cybernetics as brain sci-
ence, and we can note here that it is a different notion from the one I associ-
ated with Walter and the tortoise in the previous chapter. There “adaptation”
referred to a sensitive spatial engagement with the environment, while for
Ashby the defining feature of adaptation was finding and maintaining a rela-
tion of dynamic equilibrium with the world. This divergence lay at the heart
of their different contributions to cybernetics.
Why should the readers of the Journal of Mental Science be interested in all
this? Ashby's idea unfolded in two steps. One was to explain that dynamic equi-
librium was a key feature of life. A tendency for certain “essential variables” to
remain close to some constant equilibrium value in the face of environmental
fluctuations was recognized to be a feature of many organisms; Ashby referred
to the pH and sugar levels of the blood and the diameter of the pupil of the
eye as familiar examples. Tilted cubes and thermostats could thus be seen as
formal models for real organic adaptive processes—the mechanisms of ho-
meostasis , as it was called, though Ashby did not use that word at this point.
And Ashby's second step was to assert that “in psychiatry its importance [i.e.,
the importance of adaptiveness] is central, for it is precisely the loss of this