ROSS ASHBY - The Cybernetic Brain - page 116

Figure 4.5. changes of field in an ultrastable system. source: w. r. ashby, Design
for a Brain (london: chapman & Hall, 1952), 92, fig. 8/7/1. (with kind permission
from springer science and business media.)
Figure 4.5 is, then, an abstract diagram of how an ultrastable system such as
a homeostat finds its way to state of equilibrium in a process of trial and error,
and I want to make two comments on it. The first is ontological. The basic con-
ceptual elements of Ashby's cybernetics were those of the sort analyzed in this
figure, and they were dynamic —systems that change in time. Any trace of sta-
bility and time independence in these basic units had to do with the specifics of
the system's situation and the special circumstance of having arrived at a stable
state. Ashby's world, one can say, was built from such intrinsically dynamic
elements, in contrast to the modern ontology of objects carrying unvarying
properties (electrons, quarks). My second comment is historical but forward
looking. In Design for a Brain , one can see Ashby laboriously assembling the
technical elements of what we now call complex systems theory. For those who
know the jargon, I can say that Ashby already calls diagrams like those of figure
4.5 “phase-space diagrams”; the points at which the arrows converge in panels
III and IV are what we now call “attractors” (including, in Ashby's diagrams,
both point and cyclical attractors, but not “strange” ones); and the unshaded
area within panel IV is evidently the “basin of attraction” for the central at-
tractor. Stuart Kauffman and Stephen Wolfram, discussed at the end of this
chapter, are among the leaders of present-day work on complexity.
Now for matters of substance. Following Ashby, I have so far described
the possible relation of the homeostat to the brain in abstract terms, as both
being adaptive systems. In Design for a Brain , however, Ashby sought to evoke
more substantial connections. One approach was to point to real biological