Homeostasis is the maintenance of relatively stable internal conditions in a living system despite changes in the external environment. The term was coined by Walter Cannon in 1926, drawing on Claude Bernard’s earlier concept of the milieu intérieur — the idea that the internal environment of an organism must remain constant for life to continue.
The mechanism is feedback: a sensor detects deviation from a set point, a controller compares the deviation to the target, and an effector acts to reduce the deviation. Body temperature, blood pH, glucose concentration — these are maintained not by static equilibrium but by continuous corrective activity. Homeostasis is dynamic stability: the system is always moving, always correcting, and the appearance of constancy is the product of ceaseless adjustment.
This makes homeostasis a biological instance of cybernetic feedback regulation. W. Ross Ashby’s ultrastability model generalized Cannon’s homeostasis: a system maintains essential variables within viable limits by reorganizing its internal structure when simple feedback proves insufficient. The connection to autopoiesis is direct — an autopoietic system maintains its own organization through its own operations, and homeostasis is one of the mechanisms by which it does so.
For the relational framework, homeostasis demonstrates that biological stability is not a property of substances but a property of relations. The temperature of the body is not a fixed attribute; it is the outcome of ongoing relations among metabolic processes, circulatory dynamics, sweat glands, and environmental conditions. Remove any relatum and the “property” disappears.
Related terms
- Autopoiesis — self-producing organization of which homeostasis is one mechanism
- Symbiosis — relational entanglement that can extend homeostatic regulation across organisms
- Tropism — directional responses that serve homeostatic functions at the organismal level