Entropy Resistance as a Physical Criterion for Life: A Necessary Thermodynamic Condition for Active Organization

We propose a necessary thermodynamic condition for sustained active organization: a system is alive only when it maintains a strictly positive entropy-resistance rate on a pre-registered observable boundary, R(t) ≡−dSsys(t)/dt > 0 The criterion is derived from non-equilibrium thermodynamics under explicit assumptions (Markovian dynamics, local detailed balance). Using fluctuation theorems and the Jarzynski equality, we prove that sustained R > 0 requires external work input bounded by the Landauer cost of entropy reduction (Theorem 3). Four computational demonstrations—an agent-based living-vs.-fire model, a stochastic E. coli lifecycle, a phase diagram over energy input and internal coupling, and the Lorenz system as a Rayleigh–Bénard analogue—confirm that the criterion discriminates living systems (R > 0 sustained) from dissipative structures (R →0 at steady state). These are demonstrations of internal consistency, not empirical validation; direct measurement of R(t) on biological systems remains an open experimental challenge. The criterion is description-relative: entropy resistance depends on the choice of system boundary and observable partition, which must be pre-registered before evaluation. We propose maximum mutual information as a guiding principle for observable selection while acknowledging that practical implementation is unsolved. The framework addresses classical edge cases (viruses, dormancy, autocatalysis), provides falsification conditions, and complements rather than replaces existing definitions of life.