W. Ross Ashby was an English psychiatrist and a pioneer in cybernetics, the study of the science of communications and automatic control systems in both machines and living things. His first name was not used: he was known as Ross Ashby. His two books, Design for a Brain and An Introduction to Cybernetics, were landmark works. They introduced exact and logical thinking into the brand new discipline of cybernetics and were highly influential.
Ashby kept a journal for over 44 years in which he recorded his ideas about new theories. He started May 1928, when he was medical student at St. Bartholomew's Hospital in London. Over the years, he wrote down a series of 25 volumes totalling 7,189 pages. In 2003, these journals were given to The British Library, London, and in 2008, they were made available online as The W. Ross Ashby Digital Archive.
Cybernetics
Ross Ashby was one of the original members of the Ratio Club, a small informal dining club of young psychologists, physiologists, mathematicians and engineers who met to discuss issues in cybernetics. The club was founded in 1949 by the neurologistJohn Bates and continued to meet until 1958. The title of his book ' popularised the usage of the term 'cybernetics' to refer to self-regulating systems, originally coined by Norbert Wiener in '. The book dealt primarily with homeostatic processes within living organisms, rather than in an engineering or electronic context. Earlier, in 1946, Alan Turing wrote a letter to Ashby suggesting that Ashby use Turing's Automatic Computing Engine for his experiments instead of building a special machine. In 1948, Ashby made the Homeostat.
In An Introduction to Cybernetics, Ashby formulated his Law of Requisite Variety stating that "variety absorbs variety, defines the minimum number of states necessary for a controller to control a system of a given number of states." This law can be applied for example to the number of bits necessary in a digital computer to produce a required description or model. In response, Conant produced his so-called "Good Regulator theorem" stating that "every Good Regulator of a System Must be a Model of that System". Stafford Beer applied variety to found management cybernetics and the Viable System Model. Working independently, Gregory Chaitin followed this with algorithmic information theory. A popular paraphrasing of the law is "only complexity absorbs complexity". However, while a web search reveals many attributions to Ashby, it appears such attribution is in error. The phrase is not listed by the Cybernetics Society.
1981. Conant, Roger C.. Mechanisms of Intelligence: Ross Ashby's Writings on Cybernetics, Intersystems Publishers.
;Articles, a selection
1940. "Adaptiveness and equilibrium". In: J. Ment. Sci. 86, 478.
1945. "Effects of control on stability". In: Nature, London, 155, 242–243.
1946. "The behavioural properties of systems in equilibrium". In: Amer. J. Psychol. 59, 682–686.
1947. "Principles of the Self-Organizing Dynamic System". In: Journal of General Psychology. volume 37, pages 125–128.
1948. "The homeostat". In: Electron, 20, 380.
1962. "Principles of the Self-Organizing System". In: Heinz Von Foerster and George W. Zopf, Jr., Principles of Self-Organization. Republished as a in Emergence: Complexity and Organization Special Double Issue Vol. 6, Nos. 1–2 2004, pp. 102–126.