A thermodynamic basis for teleological causality.

We show how distinct terminally disposed self-organizing processes can be linked together so that they collectively suppress each other's self-undermining tendency despite also potentiating it to occur in a restricted way. In this way, each process produces the supportive and limiting boundary conditions for the other. The production of boundary conditions requires dynamical processes that decrease local entropy and increase local constraints. Only the far-from-equilibrium dissipative dynamics of self-organized processes produce these effects. When two such complementary self-organizing processes are linked by a shared substrate-the waste product of one that is the necessary ingredient for the other-the co-dependent structure that results develops toward a self-sustaining target state that avoids the termination of the whole, and any of its component processes. The result is a perfectly naturalized model of teleological causation that both escapes the threat of backward influences and does not reduce teleology to selection, chemistry or chance. This article is part of the theme issue 'Thermodynamics 2.0: Bridging the natural and social sciences (Part 1)'.