What principle allows Congress to levy taxes on individuals?

The principle that allows Congress to levy taxes on individuals is found in the Constitution. This foundational document established the framework for the federal government of the United States, including the powers and responsibilities of Congress. Specifically, Article I, Section 8 of the Constitution grants Congress the authority to levy taxes to provide for the common defense and promote the general welfare. This power was critical in enabling the federal government to fund its operations and maintain order.

In contrast, the Articles of Confederation, which were in effect prior to the Constitution, provided very limited powers to the federal government, including the inability to levy taxes directly. The Bill of Rights focuses on individual rights and liberties rather than the legislative powers of Congress, while the Virginia Plan was a proposal for the structure of the legislature which influenced the Constitutional Convention but did not directly grant tax powers. Thus, the Constitution is the correct answer as it specifically delineates Congress's authority to impose taxes.