One of the basic axioms of constitutional law is that Congress may take no action that is not authorized by the Constitution. The most obvious source of congressional authority is the enumeration of specific powers in Article I, section 8. The doctrine of implied powers allows Congress to exercise authority that is implied by these specific grants of power.

The textual justification for the doctrine of implied powers is Article I, section 8, paragraph 18, which provides that Congress shall have authority to “make all Laws which shall be necessary and proper for carrying into Execution the [enumerated] Powers.” The scope of this Necessary and Proper Clause was a subject of heated debate in the late eighteenth and early nineteenth centuries. Thomas Jefferson argued that the clause gave Congress authority only to enact measures absolutely necessary to implementation of the enumerated powers; Alexander Hamilton, by contrast, contended that the clause empowered Congress to adopt any measure having a natural relationship to the subjects specifically mentioned. The dispute was settled by Chief Justice John Marshall in McCulloch v. Maryland (1819). There, finding that Congress had authority to charter a bank, the Supreme Court clearly adopted the Hamiltonian view: “Let the end be legitimate, let it be within the scope of the constitution, and all means which are appropriate, which are plainly adapted to that end, which are not prohibited, but consistent with the letter and spirit of the constitution, are constitutional” (p. 421). Thus, the doctrine of implied powers became firmly established as a significant source of federal authority.

— Earl M. Maltz

The Oxford Companion to the Supreme Court of the United States. Copyright © 1992, 2005 by Oxford University Press. All rights reserved.