The American Enlightenment is the intellectual thriving period in the United States in the mid-to-late 18th century (1715–1789), especially as it relates to American Revolution on the one hand and the European Enlightenment on the other. Influenced by the scientific revolution of the 17th century and the humanist period during the Renaissance, the Enlightenment took scientific reasoning and applied it to human nature, society, and religion.
Politically, the age is distinguished by an emphasis upon liberty, republicanism and religious tolerance – culminating in the drafting of the United States Declaration of Independence and Constitution. Attempts to reconcile science and religion resulted in a rejection of prophecy, miracle and revealed religion, often in preference for Deism. Historians have considered how the ideas of John Locke and republicanism merged to form republicanism in the United States. The most important leaders of the American Enlightenment include Benjamin Franklin, Thomas Jefferson, John Adams and James Wilson.
The Americans closely followed English and Scottish political ideas, as well as some French thinkers such as Montesquieu. They paid little attention to Voltaire or Rousseau or to German theorists.[original research?][dubious ] John Locke was especially influential. In addition the Americans paid very close attention to the ideas of the "country party" in England, which attacked the Court party that was in power. From the Country Party the Americans picked up republicanism, which became a major component of American political values.[original research?]
Liberalism and republicanism
Since the 1960s, historians have debated the Enlightenment's role in the American Revolution. Before 1960 the consensus was that liberalism, especially that of John Locke, was paramount and that republicanism had a distinctly secondary role. The new interpretations were pioneered by J.G.A. Pocock who argued in The Machiavellian Moment (1975) that, at least in the early eighteenth-century, republican ideas were just as important as liberal ones. Pocock's view is now widely accepted. Bernard Bailyn and Gordon Wood pioneered the argument that the Founding Fathers of the United States were more influenced by republicanism than they were by liberalism. Cornell University Professor Isaac Kramnick, on the other hand, argues that Americans have always been highly individualistic and therefore Lockean.
In the decades before the American Revolution (1776), the intellectual and political leaders of the colonies studied history intently, looking for guides or models for good (and bad) government. They especially followed the development of republican ideas in England. Pocock explained the intellectual sources in the United States:
The Whig canon and the neo-Harringtonians, John Milton, James Harrington and Sidney, Trenchard, Gordon and Bolingbroke, together with the Greek, Roman, and Renaissance masters of the tradition as far as Montesquieu, formed the authoritative literature of this culture; and its values and concepts were those with which we have grown familiar: a civic and patriot ideal in which the personality was founded in property, perfected in citizenship but perpetually threatened by corruption; government figuring paradoxically as the principal source of corruption and operating through such means as patronage, faction, standing armies (opposed to the ideal of the militia), established churches (opposed to the Puritan and deist modes of American religion) and the promotion of a monied interest — though the formulation of this last concept was somewhat hindered by the keen desire for readily available paper credit common in colonies of settlement. A neoclassical politics provided both the ethos of the elites and the rhetoric of the upwardly mobile, and accounts for the singular cultural and intellectual homogeneity of the Founding Fathers and their generation.
The commitment of most Americans to these republican values made inevitable the American Revolution, for Britain was increasingly seen as corrupt and hostile to republicanism, and a threat to the established liberties the Americans enjoyed.
Leopold von Ranke 1848 claims that American republicanism played a crucial role in the development of European liberalism:
By abandoning English constitutionalism and creating a new republic based on the rights of the individual, the North Americans introduced a new force in the world. Ideas spread most rapidly when they have found adequate concrete expression. Thus republicanism entered our Romanic/Germanic world.... Up to this point, the conviction had prevailed in Europe that monarchy best served the interests of the nation. Now the idea spread that the nation should govern itself. But only after a state had actually been formed on the basis of the theory of representation did the full significance of this idea become clear. All later revolutionary movements have this same goal.... This was the complete reversal of a principle. Until then, a king who ruled by the grace of God had been the center around which everything turned. Now the idea emerged that power should come from below.... These two principles are like two opposite poles, and it is the conflict between them that determines the course of the modern world. In Europe the conflict between them had not yet taken on concrete form; with the French Revolution it did.
"Life, Liberty and the pursuit of Happiness"
Many historians find that the origin of this famous phrase derives from Locke's position that "no one ought to harm another in his life, health, liberty, or possessions." Others suggest that Jefferson took the phrase from Sir William Blackstone's Commentaries on the Laws of England. Others note that William Wollaston's 1722 book The Religion of Nature Delineated describes the "truest definition" of "natural religion" as being "The pursuit of happiness by the practice of reason and truth."
That all men are by nature equally free and independent, and have certain inherent rights, of which, when they enter into a state of society, they cannot, by any compact, deprive or divest their posterity; namely, the enjoyment of life and liberty, with the means of acquiring and possessing property, and pursuing and obtaining happiness and safety.
The United States Declaration of Independence, which was primarily written by Jefferson, was adopted by the Second Continental Congress on July 4, 1776. The text of the second section of the Declaration of Independence reads:
Both the Moderate Enlightenment and a Radical or Revolutionary Enlightenment were reactions against the authoritarianism, irrationality and obscurantism of the established churches. Philosophers such as Voltaire depicted organized Christianity as a tool of tyrants and oppressors and as being used to defend monarchism, it was seen as hostile to the development of reason and the progress of science and incapable of verification.
An alternative religion was Deism, the philosophical belief in a deity based on reason, rather than religious revelation or dogma. It was a popular perception among the philosophes, who adopted deistic attitudes to varying degrees. Deism greatly influenced the thought of intellectuals and Founding Fathers, including John Adams, Benjamin Franklin, perhaps George Washington and, especially, Thomas Jefferson. The most articulate exponent was Thomas Paine, whose The Age of Reason was written in France in the early 1790s, and soon reached the United States. Paine was highly controversial; when Jefferson was attacked for his Deism in the 1800 election, Republican politicians took pains to distance their candidate from Paine.
Enlightened Founding Fathers, especially Benjamin Franklin, Thomas Jefferson, James Madison and George Washington, fought for and eventually attained religious freedom for minority denominations. According to the founding fathers, the United States should be a country where peoples of all faiths could live in peace and mutual benefit. James Madison summed up this ideal in 1792 saying, "Conscience is the most sacred of all property." 
- Age of Enlightenment
- American Revolution
- Benjamin Franklin
- Common Sense (pamphlet) – by Thomas Paine
- Jefferson Bible
- Liberal democracy
- Secular state
- Separation of Church and State
- The Age of Reason – by Thomas Paine
- Thomas Jefferson
- Thomas Paine
- United States Declaration of Independence
- Paul M. Spurlin, Montesquieu in America, 1760-1801 (1941)
- Jerome Huyler, Locke in America: The moral philosophy of the founding era (1995)
- See for example, Vernon L. Parrington, Main Currents in American Thought (1927) online at 
- Shalhope (1982)
- Isaac Kramnick, Ideological Background," in Jack. P. Greene and J. R. Pole, The Blackwell Encyclopedia of the American Revolution (1994) ch 9; Robert E. Shallhope, "Republicanism," ibid ch 70.
- Trevor Colbourn, The Lamp of Experience: Whig History and the Intellectual Origins of the American Revolution (1965) online version
- Pocock, The Machiavellian Moment p 507
- Bailyn, Bernard. The Ideological Origins of the American Revolution (1967)
- quoted in Becker 2002, p. 128
- J. R. Pole, The pursuit of equality in American history (1978) p. 9
- Locke, John (1690). Two Treatises of Government (10th edition). Project Gutenberg. Retrieved January 21, 2009.
- Paul Sayre, ed., Interpretations of modern legal philosophies (1981) p 189
- James W. Ely, Main themes in the debate over property rights (1997) p. 28
- Sanford, Charles B. The Religious Life of Thomas Jefferson (1987) University of Virginia Press, ISBN 0-8139-1131-1
- Eric Foner, Tom Paine and Revolutionary America (1977) p 257
- Bryan-Paul Frost and Jeffrey Sikkenga, History of American political thought (2003) p. 152
- Franklin, Benjamin "Essays of Benjamin Franklin: Moral, Social and Scientific" (2001) University Press of the Pacific, ISBN 0-89875-162-4
- The Jefferson Bible: The Life and Morals of Jesus of Nazareth (2006) Dover Publications paperback: ISBN 0-486-44921-1
- The Jefferson Bible, (2006) Applewood Books hardcover: ISBN 1-55709-184-6
- The Jefferson Bible, introduction by Cyrus Adler, (2005) Digireads.com paperback: ISBN 1-4209-2492-3
- The Jefferson Bible, introduction by Percival Everett, (2004) Akashic Books paperback: ISBN 1-888451-62-9
- The Jefferson Bible, (2001) Beacon Press hardcover: ISBN 0-8070-7714-3
- The Jefferson Bible, introduction by M.A. Sotelo, (2004) Promotional Sales Books, LLC paperback
- Jefferson’s “Bible:” The Life and Morals of Jesus of Nazareth, introduction by Judd W. Patton, (1997) American Book Distributors paperback: ISBN 0-929205-02-2
- Paine, Thomas. The Age of Reason, The Complete Edition World Union of Deists, 2009. ISBN 978-0-939040-35-3
- Paine, Thomas. The Age of Reason. Ed. Philip Sheldon Foner. New York: Citadel Press, 1974. ISBN 0-8065-0549-4.
- Paine, Thomas. Thomas Paine: Collected Writings. Ed. Eric Foner. Library of America, 1995. ISBN 1-883011-03-5.
- Paine, Thomas. Common Sense (1982) Penguin Classics, ISBN 0-14-039016-2
- Paine, Thomas. The Life and Major Writings of Thomas Paine. Ed. Philip S. Foner. Replica Books, 2000. ISBN 0-7351-0077-2.
- Paine, Thomas. The Thomas Paine Reader. Eds. Michael Foot and Isaac Kramnick. New York: Penguin Books, 1987. ISBN 0-14-044496-3.
- Paine, Thomas (Foner, Eric, editor), 1993. Writings. Library of America. Authoritative and scholarly edition containing Common Sense, the essays comprising the American Crisis series, Rights of Man, The Age of Reason, Agrarian Justice, and selected briefer writings, with authoritative texts and careful annotation.
- Paine, Thomas (Foner, Philip S., editor), 1944. The Complete Writings of Thomas Paine, 2 volumes. Citadel Press.
- Smith, James Morton, ed. The Republic of Letters: The Correspondence between Thomas Jefferson and James Madison, 1776–1826, 3 vols. (1995)
- Aldridge, A. Owen, (1959). Man of Reason: The Life of Thomas Paine. Lippincott.
- Cunningham, Noble E. In Pursuit of Reason (1988) well-reviewed short biography of Jefferson.
- Thomas Jefferson, Political Writings ed by Joyce Appleby and Terence Ball. Cambridge University Press. 1999 online
- Weinberger, Jerry "Benjamin Franklin Unmasked: On the Unity of His Moral, Religious, and Political Thought" (2008) University Press of Kansas, ISBN 0-7006-1584-9
- Allen, Brooke Moral Minority: Our Skeptical Founding Fathers (2007) Ivan R Dee, Inc, ISBN 1-56663-751-1
- Bailyn, Bernard The Ideological Origins of the American Revolution (1992) Belknap Press of Harvard University Press, ISBN 0-674-44302-0
- Bedini, Silvio A Jefferson and Science (2002) The University of North Carolina Press, ISBN 1-882886-19-4
- Cassirer, Ernst Philosophy of the Enlightenment (1932), [English translation 1951] Princeton University Press, ISBN 0-691-01963-0
- Cohen, I. Bernard Benjamin Franklin's Science (1996) Harvard University Press, ISBN 0-674-06659-6
- Cohen, I. Bernard Science and the Founding Fathers: Science in the Political Thought of Jefferson, Franklin, Adams and Madison (1995) WW Norton & Co, ISBN 0-393-03501-8
- Dray, Philip Stealing God's Thunder: Benjamin Franklin's Lightning Rod and the Invention of America (2005) Random House, ISBN 1-4000-6032-X
- Ellis, Joseph. "Habits of Mind and an American Enlightenment," American Quarterly Vol. 28, No. 2, Special Issue: An American Enlightenment (Summer, 1976), pp. 150–164 in JSTOR
- Ferguson, Robert A. The American Enlightenment, 1750–1820 (1997) Harvard University Press, ISBN 0-674-02322-6
- Gay, Peter The Enlightenment: The Rise of Modern Paganism (1995) W. W. Norton & Company, ISBN 0-393-31302-6; The Enlightenment: The Science of Freedom (1996) W. W. Norton & Company, ISBN 0-393-31366-2
- Israel, Jonathan A Revolution of the Mind – Radical Enlightenment and the Intellectual Origins of Modern Democracy (2009) Princeton University Press, ISBN 0-691-14200-9
- Jayne, Allen Jefferson's Declaration of Independence: Origins, Philosophy and Theology (2000) The University Press of Kentucky, ISBN 0-8131-9003-7; [traces TJ's sources and emphasizes his incorporation of Deist theology into the Declaration.]
- Koch, Adrienne. "Pragmatic Wisdom and the American Enlightenment," William and Mary Quarterly Vol. 18, No. 3 (Jul., 1961), pp. 313–329 in JSTOR
- May, Henry F. The Enlightenment in America (1978) Oxford University Press, USA, ISBN 0-19-502367-6
- McDonald, Forrest Novus Ordo Seclorum: Intellectual Origins of the Constitution (1986) University Press of Kansas, ISBN 0-7006-0311-5
- Meyer D. H. "The Uniqueness of the American Enlightenment," American Quarterly Vol. 28, No. 2, Special Issue: An American Enlightenment (Summer, 1976), pp. 165–186 in JSTOR
- Nelson, Craig Thomas Paine: Enlightenment, Revolution, and the Birth of Modern Nations (2007) Penguin, ISBN 0-14-311238-4
- Richard, C.J. Founders and the Classics: Greece, Rome and the American Enlightenment (1995) Harvard University Press, ISBN 0-674-31426-3
- Sanford, Charles B. The Religious Life of Thomas Jefferson (1987) University of Virginia Press, ISBN 0-8139-1131-1
- Sheridan, Eugene R. Jefferson and Religion, preface by Martin Marty, (2001) University of North Carolina Press, ISBN 1-882886-08-9
- Staloff, Darren Hamilton, Adams, Jefferson: The Politics of Enlightenment and the American Founding. (2005) Hill & Wang, ISBN 0-8090-7784-1
- Wood, Gordon S. The Radicalism of the American Revolution (1993) Vintage, ISBN 0-679-73688-3