feedbacked Tao

One of the most powerful ideas of the twentieth century -particularly in the postwar-, for design and description of natural and artificial systems was to take the output of a black box and return it at the input:

Depending on whether this back-action output is added (positive feedback) or subtracted (negative feedback) we get the destruction (runaway) or the stabilization of the system.

In the first case an increase in the output increases the input which in turn increases the output again and so on, until the destruction of the system, while in the second case any perturbation of the input is compensated by the feedback and the system reaches a controlled steady state.

Ignoring the input and the output we see that now the black box has an external loop process of circular-recursive type:

Almost all the natural and artificial systems are based on stationary negative-feedback circular processes, for example in electronics control systems the classic scheme is:

The feedback process stabilizing (or destructive) is retrospectively understood since a long time, as evidenced by the classical figure of Ouroboros, the snake biting its tail continually recreating: