[320]
On separation of powers, Adams wrote that, "Power must be opposed to power, and interest to interest."[321] This sentiment was later echoed by James Madison's statement that, "[a]mbition must be made to counteract ambition," in Federalist No. 51, explaining the separation of powers established under the new Constitution.[321][322] Adams believed that human beings were naturally desirous of furthering their own ambitions, and a single democratically elected house, if left unchecked, would be subject to this error, and therefore needed to be checked by an upper house and an executive. He wrote that a strong executive would defend the people's liberties against "aristocrats" attempting to take it away.[323]
Adams first saw the new United States Constitution in late 1787. To Jefferson, he wrote that he read it "with great satisfaction."Adams expressed regret that the president would be unable to make appointments without Senate approval and over the absence of a Bill of Rights. "Should not such a thing have preceded the model?"he asked.