International Encyclopedia of Systems and Cybernetics

"The aim or objective of a living system (or artefact) as indicated by the standards embodied in its program of controls, including those standards acquired by learning" (J.Z. YOUNG, 1974, p.297)

This definition by-passes the willfulness problem, at least in the case of most living systems, since most of them have no possibility of control over their own program.

However, in their 1943 fundational paper about "Behavior, purpose and teleology", A. ROSENBLUETH, N. WIENER and J. BIGELOW wrote: "The basis of the concept of purpose is the awareness of "voluntary activity"… The term purposeful is meant to denote that the act or behavior may be interpreted as directed to the attainment of a goal, i.e., to a final condition in which the behaving object reaches a definite correlation in time or in space with respect to another object or event. Purposeless behavior then is that which is not interpreted as directed to a goal".

And: "… the purpose of voluntary acts is not a matter of arbitrary interpretation but a physiological fact. When we perform a voluntary action what we select voluntarily is a specific purpose, not a specific movement" (1943, p.19).

These authors also state: "All purposeful behavior may be considered to require negative feedback. If a goal is to be attained, some signals from the goal are necessary at some time to direct the behavior".

These quotations call for some remarks;

1. Are living systems, or artefacts "goals" to be distinguished, and if so, how? The goal of a cybernetic artefact is introduced by its builder. However, once there, it becomes an autonomous feature of the artefact.

2. Is the presence of a negative feedback always a signal of the existence of a "goal", or "purpose"?

3. Goals are, by necessity, the present representation of a state to be attained or maintained. There is thus no paradox about a supposed influence of the future upon the present.

G. PASK distinguishes "purposes for systems", as the function we assign to them within some larger context and "purposes in systems" as the internal goals driving their behavior". He adds that "… we cannot make sense of a system without assuming a purpose for or in it thus all systems are purposeful" (1969 – as quoted by W.R. WINBURN, 1991, p.555)

Or course, such assumptions are "ours".

As to the purpose of artifacts, until now at least, it is strictly defined by their constructors. An intriguing question would be to define the possible purposes of artifacts which would "acquire standards by learning".

J.van GIGCH offers a context view of purpose: Inanimate systems are devoid of visible purpose. "They acquire a specific purpose or function when they enter into relationship with other subsystems in the context of a larger system" (1978, p.14). Purpose has thus a reactive character.

According to W.T. POWERS, "In a control-system model, a purpose is simply a reference signal. The reference signal determines the state to which an input, a sensory signal, will be brought and at which it will be maintened. In nearly all control systems, the sensory input represents the state of some external variable affected by the system's action. So whatever action brings the sensory signal to match with the reference signal perforce brings the sensed external variable to some specific reference state"(from POWERS' internet page, 1999). This implies some internal feedback embedded within the control level.

Thus, what is meant by purpose in every specific case, is defined by the system's level of organization.

Consequently, the very diverse uses of the term may easily lead to semantic muddles and conceptual confusion.

On the other hand T.W. DEACON, in a 2001 review of G. CZIKO's book "The things we do"(2000), mentions that "According to POWERS, purpose is concretly represented as a perceptual reference signal in some internal feedback loop embedded in other higher order feedback loops"

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