EQUIFINALITY PRINCIPLE
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1139 ▶ |
| Object type | General information |
- “In open systems… the same final state may be reached from different initial conditions and in different ways” (L.von BERTALANFFY, 1956, p.4).
BERTALANFFY observes that this is not the case in closed systems and gives as an example the perfect previsibility of the movement of the planets and of their position at some t$_{1}$ moment knowing their position at t$_{0}$.(Ibid).
Let us remember that, nowadays, this previsibility is not anymore considered perfect (see:Chaos), which does not anymore allows for the unrestricted generalization of the equifinality principle to the physical systems.
The equifinality principle, as a conceptual model, replaces in biology the vitalist concept proposed by the German biologist H. DRIESCH based on his experiences on the development of sea urchins embryos: “The same final result, a normal individual of the sea urchin, can develop from a complete ovum, from each half of a divided ovum, or from the fusion product of two whole ova. The same applies to embryos of many other species, including man, where identical twins are the product of the splitting of one ovum” (Ibid).
BERTALANFFY adds: “… equifinality is not a mathematical characteristic but a physical characteristic of (certain) open systems. It does not depend on the structure of the system equations but on the meaning of the parameters so that formally identical equations may apply to non-equifinal closed systems as well as to equifinal open systems. However, the equifinal case where the final state depends only on the reaction and transport parameters, and not on the initial conditions, is found only in open systems” (Ibid).
In spite of its evident importance, the equifinality principle presents serious interpretative difficulties. For example, the same system necessarily starts from one and only one initial set of conditions and while it could follow different paths for its transformations, it will really take one, and only one.
Let us also remember the semantic ambiguities concealed under the concepts of “open”, “closed” and “isolated” system.