Chapter 50: The Self-Enrichment Ladder: E₀–E₃ Complete

The complete self-enrichment ladder is presented: E₀ (mathematics: objects + laws), E₁ (physics: sectors + couplings), E₂ (life: codes + organisms), E₃ (metaphysics: observers + meaning). Three identity regimes—phenotype-mortal/genotype-stable (biology), phenotype-stable/genotype-stable (BH-life), and phenotype-mortal/genotype-mortal (non-Life)—classify all carriers exhaustively. The Enrichment Saturation Theorem establishes that E₄ collapses to E₃: the reflection automorphism ρ generates exactly four orbits, and no genuinely new ontic structure arises beyond the third self-enrichment (full proof: VII.T06). Finally, τ is positioned as a third option between vitalism and pure emergence: Life is the categorical structure recognizing itself at E₂.