W. Ross Ashby

Biography

William Ross Ashby (6 September 1903, London – 15 November 1972) was an English psychiatrist and one of the founders of cybernetics — described by Stafford Beer and others as the field's major theoretician after Norbert Wiener. He trained in medicine at Cambridge and St Bartholomew's Hospital and spent most of his career in psychiatric research, at the Barnwood House Hospital in Gloucester and then as director of the Burden Neurological Institute in Bristol. From 1960 to 1970 he was professor of biophysics and electrical engineering at the University of Illinois at Urbana-Champaign, working in Heinz von Foerster's Biological Computer Laboratory. He was an original member of the Ratio Club and president of the Society for General Systems Research from 1962 to 1964.

The Homeostat

In 1948 Ashby built a device from four surplus RAF bomb control units, each capable of sensing the others' output and adjusting its own. Connected together, the assembly would respond to any disturbance by searching, apparently at random, through its possible configurations until it found one that returned all four units to equilibrium — and it would do this even for disturbances its builder had not anticipated, including having its own wiring reversed. Wiener called it "one of the great philosophical contributions of the present day." The homeostat was the first working demonstration that adaptive, goal-seeking behaviour could be produced by a machine with no representation of its goal, and it remains the reference example for ultrastability.

Key Ideas

• Ultrastability. A system is ultrastable if, when its essential variables are driven outside their survivable range, it changes its own organisation until they return. Ashby argued this, rather than any specific mechanism, is what adaptation is.
• The Law of Requisite Variety. "Only variety can destroy variety." A regulator can only control a system to the extent that it has at least as many distinguishable states as the disturbances it must absorb. This is the single most-cited result in cybernetics and the foundation of Beer's variety engineering.
• The Black Box. Ashby formalised the method of studying a system solely through the relation between its inputs and outputs, without access to its internals — a method now standard well beyond cybernetics.
• Self-organisation. Ashby's 1947 paper "Principles of the Self-Organizing Dynamic System" and his 1962 "Principles of the Self-Organizing System" set the terms for later work on emergence, and included the deflationary observation that every isolated determinate dynamic system is self-organising in a trivial sense — so the interesting question is always what the organisation is for.

Selected Works

• Design for a Brain: The Origin of Adaptive Behaviour. London: Chapman & Hall, 1952 (2nd ed. 1960).
• An Introduction to Cybernetics. London: Chapman & Hall, 1956. Long out of print and now freely available; still the clearest textbook the field produced.

Relevance to Cyborg Anthropology

The law of requisite variety is the most portable idea in cybernetics and applies directly to interface and institutional design: a system that offers fewer responses than the situations its users encounter will fail, and the failure will look like user error. Ashby also supplies the intellectual bridge between biological regulation and machine regulation on which the whole cyborg concept rests.

Related Reading

• Stafford Beer
• Norbert Wiener
• Cybernetics
• Project Cybersyn

External Links

• The W. Ross Ashby Digital Archive