Congress has given the courts power to develop substantive law, and areas where a federal rule of decision is necessary to protect uniquely federal interests. The U.S. Congress has given courts power to formulate common law rules in areas such as admiralty law, antitrust, bankruptcy law, interstate commerce, and civil rights. Congress often lays down broad mandates with vague standards, which are then left to the courts to interpret, and these interpretations eventually give rise to complex understandings of the original intent of Congress, informed by the courts' understanding of what is just and reasonable. Furthermore, in the 1943 case of Clearfield Trust Co. v. United States, the Court recognized that federal courts could still create federal common law, albeit in limited circumstances where federal or Constitutional interests were at stake, Congress had inadequately addressed the situation sub judice, and the application of individual state laws in various jurisdictions would create unacceptable levels of diversity or uncertainty. When fashioning new federal common law, the Court may either adopt a reasonable state law, look to its own precedent, or create new law. Congressional repeal of federal common law Federal common law is valid only to the extent that Congress has not repealed the common law. The Supreme Court has explained that, "when Congress addresses a question previously governed by a decision resting on federal common law, the need for such an unusual exercise of law-making by federal courts disappears." During the era when the Constitution was written, it was understood that common law was alterable by legislatures. For example, Alexander Hamilton emphasized in The Federalist Papers that the New York Constitution made the common law subject "to such alterations and provisions as the legislature shall from time to time make concerning the same." Thus, even when a federal court has authority to make common law, that law is subject to alteration by Congress. This principle finds expression in the first sentence of the Constitution: "All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives." Federal criminal common law In the Virginia Senate debate over ratification of the Bill of Rights, Senator George Mason objected to the words "Congress shall make no law" in the First Amendment, on the grounds that "arbitrary decisions of judges" might violate those same rights. However, the U.S. Supreme Court stated in