Tool Module: Cybernetics

Louis Couffignal, one of the pioneers of cybernetics, defined it as “the art of assuring efficiency of action.” A less poetic definition is that cybernetics is the science of dynamic relations between the parts of a whole, meaning relations that change over time.

Cybernetics has applications in industry and biology as well as in art, not to mention computer science, which can be regarded as an application of cybernetics. The many different Internet-related terms that start with “cyber-“ (cyberspace, cybercafé, etc.) are all derived from the word cybernetics.

Because cybernetics is so closely linked with the concepts of structures and levels of organization, it forces us to clearly define certain of their elements, whose interaction can be diagrammed as follows.


First, an effector is a mechanism that produces certain effects.

Factors are the necessary conditions for the operation of the effector.

Feedback is a phenomenon by which effects can influence one or more factors that act on the effector. This feed-back makes it possible to pursue a goal–in other words, to move toward a desired state or maintain a behaviour despite disturbances due to the external environment.

The purpose of an effector is to achieve a certain value of the effect. An effector that tries to keep the effect at a constant value is called a constancy effector. The vast majority of the physiological mechanisms that help to maintain internal equilibrium in living organisms are constancy effectors.

On the other hand, an effector that tries to move the effect toward a maximum value is called a tendency effector.

A constancy effector is said to be “regulated” if it is subject to feedback whose sign is the opposite of the factor’s.

In contrast, tendency effectors are subject to feedback whose sign is the same as that of the factor on which it acts.

The term "regulator" refers to a constancy effector that maintains equilibrium at close to an ideal value, fluctuating around a mean thanks to the negative feedback loop.

A regulator can also have a servomechanism. A servomechanism is a control that is external to the system and that acts on the feedback loop to modify its value.



For example, a thermostat set to keep the temperature of a room at 21 degrees Celsius is a regulator. But if we want to raise the room temperature to 25 degrees, we must intervene from outside the system by moving the thermostat control to the new value.

This concept of servomechanisms is central to the science of physiology, because it implies the existence of various levels of organization in living organisms. Regulated systems are found at every level of organization in living organisms. But each of these regulators is also subject to a servomechanism: the information that it receives from the higher levels surrounding it. In living systems, servomechanisms are what allows the various levels to work together harmoniously to maintain the structure of the organism as a whole.

For example, at the molecular level, the set of enzymes necessary for a particular biochemical reaction can be regarded as a regulator. But this regulator is influenced by an external control from the next level up–in this case, the cell. The cell is another regulated system, as exemplified by the way that a neuron maintains its resting membrane potential. But the cell too is subject to a servomechanism: the information that it receives from the organ to which it belongs.The organ in turn receives servomechanism control information from the system to which it belongs (nervous, vascular, endocrine, etc.), the system does so from the organism as a whole, and the organism does so from its external environment.

This chain of servomechanisms, linking the molecule to the organism to humanity as a whole within its cosmic environment, is the result of the evolution of living structures. This evolution itself is part of the tendency of the universe to become more complex locally.

An organism is thus an open system from an information standpoint, because information flows down to every level of organization from the level above it. But the information also flows upward, because all the levels of organization are already contained in potential form in the DNA of the fertilized egg.

In contrast to the "structural information" that is supplied by the genes and modified by the environment to produce a particular individual, we can therefore also distinguish "circulating information", which is carried mainly by the nervous and endocrine systems.

While structural information serves, for example, to distinguish a person from an elephant, circulating information serves to maintain the organism’s overall structure and the integrity of each level of organization. By accomplishing its own purpose, each of these regulated systems helps to accomplish the purpose of the system as a whole. And it is the circulating information that accomplishes much of the work of the servomechanism, or external control, at every level of organization.

Cybernetics thus constitutes an essential tool for understanding living things, because it reveals the levels of organization and the dynamic linkages between them. The concept of servomechanisms also helps us to understand the concept of structure, meaning the entire set of relationships among all the parts of a whole. A structure cannot be reduced to the sum of its parts, because these parts establish relationships among themselves, and it is the entire set of these relationships that defines the structure of an organism. "The whole is greater than the sum of its parts."

Thus, in any organism, the structure consists of a hierarchy of levels of organization, each of which constitutes the control of a servomechanism that ensures the functional cohesion of the whole. We can thus clearly see why cybernetics is described as the science that studies the dynamics of structures.



This nested hierarchy of organizational levels is sometimes compared with a set of nested Russian dolls. But this analogy is not really very accurate. You can remove all the smaller dolls from inside the largest one, and it will still retain its form. But if you did the same thing to a living body, you would destroy its servomechanisms and turn it into a corpse.

As cybernetics tells us, life is both a system and information, whereas a machine is a system that feeds on information. If you cut the power to a computer, it will no longer be able to use the information supplied to it, but it will still be a computer, ready to work again when the power comes back on. But if you cut off a plant’s sunlight or an animal’s food, it will quickly become an inert body and start to decompose. Its structure coincides with the energy that feeds it and that it transforms or, more precisely, informs.