GOAL-SEEKING SYSTEM
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1447 ▶ |
| Object type | General information, Epistemology, ontology or semantics |
W. R. ASHBY writes: “Every stable system has the property that if displaced from a state of equilibrium and released, the subsequent movement is so matched to the initial displacement that the system is brought back to the state of equilibrium. A variety of disturbances will therefore evoke a variety of matched reactions.
- “This pairing of the line of return to the initial displacement has sometimes been regarded as ”intelligent“ and peculiar to living things. But a simple refutation is given by the ordinary pendulum: if we displace it to the right, it develops a force which tends to move it to the left; and if we displace it to the left, it develops a force which tends to move it to the right. Noticing that the pendulum reacted with forces which though varied in direction always pointed towards the centre, the mediaeval scientist would have said ”the pendulum seeks the centre“. By this phrase he would have recognised that the behaviour of a stable system may be described as ”goal seeking“. Without introducing any metaphysical implications we may recognise that this type of behaviour does occur in the stable dynamic systems” (1950, p.54).
As human systems (personal and social) describe their goals and pursue them in a willful way (i.e. an at least seemingly not rigorously pre-determined way), one may wonder if the words “goal-seeking” should be used for all types of systems.
Even a biological system as an animal, which exhibits many kinds of complex activities is not simply responding passively to a stimulus, which is the case with the pendulum.
In any case, a true goal-seeking seems to necessarily imply corrective feedback.
ASHBY himself states: “machines with feedback are not subject to the oft-repeated dictum that machines must act blindly and cannot correct their errors” (p.55) and moreover: “A system which possesses feedback is usually actively stable or actively unstable; and whether it is stable or unstable depends on the quantitative details of the particular arrangement” (p.54).
See also
LE CHATELIER Principle.