…All this is mistaken. What the system really needs, and all it needs, is
a way of measuring it’s own internal tendency to depart from stability, and a set of rules for experimenting with responses,
which will tend back to an internal equilibrium. Then there is no need to know in advance what might cause a disturbance;
there is no need to know what has caused a disturbance. To be aware of something happening and label it disturbance, and to
be able to alter internal states until the effects of the disturbance are offset, is enough.A system that can do this, that can survive arbitrary and unforecast interference, is known to cyberneticians
as an ultrastable system (following Ashby’s nomenclature).