摘要：The article presents justification of the twin aims in diversity cases and systematic analysis of its role in federal and state court. It informs that twin aim protects state interests with separation of powers in which state law is incorporated into federal procedural common law in order to serve federal interests. In the U.S. Supreme Court case Erie Railroad Co. v. Tompkins, the Court held that federal courts can not create federal common law under diversity jurisdiction.
关键词：Separation of powers; State laws; Common law; Diversity jurisdiction; Erie Railroad Co. v. Tompkins (Supreme Court case)
