Ashby's LOV LO1045

a kefalas (
Wed, 03 May 95 13:45:11 EDT

Re: LO691, 4/4/1995

A few weeks ago Michael McMaster expressed his wisdom on the
Law of Requisite Variety with the safe proviso " as far as I
know." He wrote " the law of requisite variety states that
the controlling part of the system is the part with the most
flexibility...the law, as far as I know, was developed from
the study of complex but non-living systems.

Since both the statement of the LOV and its
origins aren't quite right, I'd like to set the record
straight by offering a brief description of the origins of
the LOV. By the way LOV is my abbreviation!

The LOV is know as Ross Ashby' s Law of Requisite Variety and
it states that "only variety can destroy variety." [W.R.
Ashby, Introduction to Cybernetics, p. 207]. Stafford Beer,
puts it in a bit more elaborate way: he states that
"control can be obtained only if the variety of the
controller is at least as great as the variety of the
situation to be controlled." [Beer, The Brain of the Firm,
p. 54]. While Ashby's Chapter 11 on Requisite Variety uses
"plays or games" to explain the LOV, the previous chapters
explained regulation "from the biological point of view."
And to mimic McMaster, as far I know, W.R. Ashby was NOT a
linguist. Even though McMaster's argument about flexibility
and resistance seems to make intuitive sense, his
understanding of Systems Theory, a la Beer and Ashby, to
name just two of his compatriots, doesn't.

a kefalas <>