[John Adams] experience with the French philosophers only convinced him further of the need for a bicameral legislature representing the two principal social orders and, equally important, an independent executive.

I think [John Adams's] influence on the federal Constitution was indirect. Many including James Madison mocked the first volume of Adams's Defence of the Constitutions of the United States in 1787. But his Massachusetts constitution was a model for those who thought about stable popular governments, with its separation of powers, its bicameral legislature, its independent judiciary, and its strong executive.

[John's Adams] description of [Benjamin] Franklin in a letter to [his wife] Abigail in 1775 is laudatory. Only when he experiences all the adulation paid to Franklin in Paris does he begin to change his tune.

History is the queen of the humanities. It teaches wisdom and humility, and it tells us how things change through time.

[ Massachusetts constitution] was [John Adams] attempt to justify that structure by the traditional notion of social estates - that the executive represented the monarchical estate, the senate the aristocratic estate, and the house of representatives the estate of the people.

[John] Adams identified himself with the political theories of [James] Harrington, [John] Locke, and [Charles-Louis] Montesquieu, whose ideas of constitutionalism, he believed, were applicable to all peoples everywhere; they were his contribution to what he called "the divine science of politics."

By the time [John Adams] came to write his Defence of the Constitutions of the United States in 1787 he had as dark a view of the American character as that of any critic in our history.