E₈ is the largest exceptional Lie algebra and appears in various approaches to unified field theory. Pentagon Physics shows that E₈ is not a foundation but a corollary — it arises as the lattice generated by both roots of the axiom σ = 1/(1+σ). The positive root σ = 1/φ generates the confined sector (mass). The negative root ψ = −φ generates the free sector (charge). Their combined geometry produces E₈ as the unique even unimodular lattice in 8 dimensions compatible with the Galois structure of ℚ(√5). E₈ is derived. It does not need to be assumed.