The *(term) for the mechanism by which information can stabilize, propagate, and evolve in a dynamic system: subsystems correct their _(output) according to the _(input) they get back from the "external world" after.

When the corrected output changes in an opposite way to the difference between the input and some point, we have <em>negative</em> feedback, which allows the subsystem to stabilize around that point that we call point of equilibrium.

In a dynamical world, where nothing can be taken for sure as definitely granted, only through feedback can one adapt to the world. Particularly, we must continually confront our theories and ideas to actual practice, and ideas that others may have, so we can trust them in any way. Ideas that cannot suffer and survive such confrontations are false.
