Introduction: The Varieties of Arbitration; Part I. Arbitration and Private Law: 1. The Liberal Case for Arbitration; 2. Constitutionalizing the Right to Arbitration; 3. Boundaries and Constraints; 4. Arbitration and the Law-Making Process; 5. The Special Case of International Commercial Arbitration; Part II. Investment Treaty Arbitration: 6. The Rise of Investment Treaty Arbitration; 7. Privileging Foreign Investors? The Equality Challenge; 8. Adjudicative Coherence and Democratic Checks on Arbitral Jurisprudence; 9. Investment Treaty Arbitration, Regional Integration, and Fragmentation of International Law; 10. The Arbitral Foundations of International Adjudication; 11. The Virtues and Limitations of State-to-State Arbitration.