"Cybernetics is concerned primarily with the construction of theories and models in science, without making a hard and fast distinction between the physical and the biological sciences. The theories and models occur both in symbols and in hardware, and by 'hardware* we shall mean a machine or computer built in terms of physical or chemical, or indeed any handleable parts. Most usually we shall think of hardware as meaning electronic parts such as valves and relays. Cybernetics insists, also, on a further and rather special condition that distinguishes it from ordinary scientific theorizing: it demands a certain standard of effectiveness... The concept of an effective procedure springs primarily from mathematics, where it is called an algorithm... The principal aims of cybernetics may be listed under three headings: (1) To construct an effective theory... [of] the principal functions of the human organism... (2) To produce the models and theory in a manner that realizes the functions of human behaviour by the same logical means as in human beings. This implies the simulation of human operations by machines... (3) To produce models which are constructed from the same colloidal chemical fabrics as are used in human beings."