Hm. No specific definition of "Life Liberty and the pursuit of happiness" either, and yet, I think we can all agree as to the SPIRIT of what the pricipals are.
HAVING a separation ensures the freedom to practice as one wishes. I would think that would be a GOOD thing... but as the CPA so deftly points out, it is only a good thing if you agree.

Back to the topic. Separation of Church and State is not found in any of the pertinent documents.
Absolutely true, and absolutely irrelevant. Separationists take this language from Thomas Jefferson's 1802 letter to the Danbury Baptists in which he argued that the Constitution created a "wall of separation between church and state." But separationists have never taken the phrase as anything more than a handy (if historically significant) summary of the intent of the religion clauses of the First Amendment. Separationist scholar Leo Pfeffer notes:

"No magic attaches to a particular verbalization of an underlying concept. The concept at issue here is more accurately expressed in Madison's phrase 'separation between Religion and Government,' or in the popular maxim that 'religion is a private matter.'" (Church, State, and Freedom)




Second, accommodationists don't apply this argument consistently. Pfeffer again:

"The phrase "Bill of Rights" has become a convenient term to designate the freedoms guaranteed in the first ten amendments; yet it would be the height of captiousness to argue that the phrase does not appear in the Constitution. Similarly, the right to a fair trial is generally accepted to be a constitutional principle; yet the term "fair trial" is not found in the Constitution. To bring the point even closer to home, who would deny that "religious liberty" is a constitutional principle? Yet that phrase too is not in the Constitution. The universal acceptance which all these terms, including "separation of church and state," have received in America would seem to confirm rather than disparage their reality as basic American democratic principles"

Other documents... well, I'd consider the Constitution to be a "Founding Document", as well as the Federalist Papers:
In the unamended constitution the government was given no authority in matters of religion: no authority to aid (promote, help, etc) or hinder religion. Matters of religion were off limits to the government, but the drafters of the Constitution were hard pressed to convince the state ratifying conventions of the built-in constitutional safeguards. Because some felt that clauses such as the Constitution's "elastic clause" might enable a future Congress to circumvent the "no power" over religion directive, Madison drafted and submitted the additional constitutional constraints that eventually became the religious clauses of the our 1st Amendment. See the Federalist Papers, # 84.

(forgive the many edits: I have REAMS of this stuff on my hard drive)

Letter from George Washington responding to a question concerning the lack of mention and or requirements as to religion and Christianity in the Constitution:

October, 1789

To the Ministers and Ruling Elders delegated to represent the churches in Massachusetts and New Hampshire, which compose the First Presbytery of the Eastward.


The tribute of thanksgiving which you offer to the gracious Father of lights, for his inspiration of our public councils with wisdom and firmness to complete the national Constitution, is worthy of men who, devoted to the pious purposes of religion, desire their accomplishment by such means as advance the temporal happiness of mankind. And here, I am persuaded, you will permit me to observe, that the path of true piety is so plain as to require but little Political attention. To this consideration we ought to ascribe the absence of any regulation respecting religion from the Magna Charta of our country.



To the guidance of the ministers of the gospel this important object is, perhaps, more properly committed. It will be your care to instruct the ignorant, to reclaim the devious; and in the progress of morality and science, to which our government will give every furtherance, we may expect confidently, the advancement of true religion and the completion of happiness. I pray the munificent rewarder of every virtue, that your agency in this good work may receive its compensation here and hereafter.





George Washington.

I got more. Want it?