Metaphors are like marriages - there is mutual agreement on their usefulness but for very different purposes.
Most of us were taught to understand secularism as the metaphoric wall of separation between church and state. But trying to derive a common understanding of the metaphoric wall is like trying to get oil back into a gushing wellhead on the ocean floor. Metaphors are great for simplifying complex definitions but when used extensively they remove all memory of the objective definition and give everyone the false idea that their subjective understanding is the "real" one.
The reason the metaphoric wall is so popular, not just in America but globally, is because the term "Secularism" has never been clearly defined itself, even amongst scholars. However, political volatility will not diminish until we have agreement on the nature of our "social contract" which will require a common definition of secularism. So, to that end, first a little history....
The metaphoric wall originally took the form of a more neighbourly hedge, when first used in 1644 by protestant theologian, Roger Williams. Williams played a significant role in founding the colony of Rhode Island and the First Baptist Church of America, and vehemently argued for the separation of church and state, to ensure that the state never contaminated the purity of religious beliefs.
Thomas Jefferson's now infamous letter of 1802 to the Danbury Baptists, was the first recorded use of the metaphoric wall in the context of explaining America's first amendment:
Believing with you that religion is a matter which lies solely between Man & his God, that he owes account to none other for his faith or his worship, that the legitimate powers of government reach actions only, & not opinions, I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should "make no law respecting an establishment of religion, or prohibiting the free exercise thereof," thus building a wall of separation between Church & State.
The metaphoric "wall of separation" was formally brought into the US constitutional case law in 1879 but the court decided that wall was not so high that it protected religious freedom to the point of allowing the practice of polygamy.
In 1947 the US Supreme Court extended the federal anti-establishment clause to the individual states but then decided that again, it was not so high as to prevent state funding for transportation to religious schools if the funding was provided on a neutral basis to parents and not directly to the schools.
The wall of separation was referenced again by the US Supreme Court in 1962 but this time disallowing mandatory school prayers, "silent or voluntary prayer," in 1985 and student-lead prayers in 2000.
The metaphoric wall is easiest to understood when both church and state were single institutions (monarchies and national churches) and there were literally well-groomed hedges separating their elaborate properties. Today, however, there are no national churches and there are no more Kings.
When we use the metaphoric wall today, the term "church" is interpreted as "religion" and "the state" means all branches of the government, and for some, even the sovereigns that replaced King George, "the electorate". Taken to the extreme, the wall of separation agrees with Plato and Marx, that democracy is the worst form of government. That only the educated should be allowed to vote - or only those who can provide reasons grounded in established evidence should be allowed to influence the political process.
Dogmatic use of the metaphor, without appreciating the changed political environment, changes the concept of secularism significantly since the days of the American founding fathers and John Locke, Voltaire and Jean Jacques Rousseau. About half of America sees this change as rational progress, and the other half sees it as a loss of liberty and the freedom of conscience. Unfortunately, the metaphoric wall makes it appear that our only choices are between religious freedom and rational progress - hence the rise in the new atheists.
Metaphors are supposed to summarize complex notions, not replace them. Our postsecular problem is that secularism has never been consistently defined. It was first coined by agnostic George Holyoake in 1851, who wanted freedom from blasphemy laws to ensure that scientific inquiry was not legally/politically restricted. So Holyoake envisioned a wall high enough to prevent the clergy from entering the legislature, courtrooms and classrooms.
In contrast, shortly thereafter in 1856, Charles Bradlaugh, an atheist, co-founded the National Secular Society in England, and used the term to refer to the eradication of religion as both a political institution and moral influence on people, much like Karl Marx. Bradlaugh wanted the wall of separation to surround the whole country, not just the legislature and schools. Holyoake wanted a neighbourly hedge; Bradlaugh wanted the Berlin wall.
Many attempts over the years to define Secularism have resulted in the use of relative descriptors such as hard/soft, open/restrictive, radical/non-radical. These descriptors, however, have only compounded the confusion because the original point of reference varies by country and time - and most lack common use across academic disciplines, most notably the courts.
The courts can, and do, avoid defining secularism because it is actually rarely used in constitutional clauses and legislation. So the metaphoric wall of separation continues as the most commonly understood definition–even by non-Americans.
Lets go back to basics. Secular constitutions were the response to the abuses of absolute monotheism—wherein both Kings and Churches, pardoned each other's abusive practices on the long-standing, mutually entrenching, myth of the divine right of kings. The word Secular is used to describe a great variety of institutions and constitutional models—but their common characteristic is the objective of divesting churches of their political authority.
As the sovereign notion of the divine right of kings was challenged, the political concept of the "social contract" was needed as the basis for establishing political authority. Individuals now agreed to abide by a country's laws because they agreed with the underlying rational values expressed in the constitution. Consequently, secular governments are accountable to rational objectives like political equality (universal suffrage, due process rights) or economic equality (communism).
At its most basic level, secular means that political authority is grounded in rational, not religious principles. Rational objectives can be measured and evaluated, providing an objective means of holding political leaders accountable and a collective sense of progress and achievement.
Building on this basic definition of secular, the following types of secularism are proposed Romantic Secularism, Rational Secularism and Postmodern Secularism. This classification provides the moderate religious right with rational terminology to express their political concerns and avoid the accusation of secretly wanting to turn America into a Christian theocracy, by being absolute monotheists. Indeed, the terminology provides truly progressive, moderate followers of any monotheistic religion, like Islam, with the same argument.
The following terms highlight critical differences between different forms of secular constitutions and reference the assumptions that put them at odds with Absolute Monotheism, their common enemy. As a quick overview here are summary definitions that are explored in more detail in Parts II, III and IV.
Romantic Secularism values democracy and freedom of conscience, placing the individual as the ultimate moral judge by creating two moral spheres - one private and one public. We recognize the government as sovereign, but that does not necessarily make it's decisions moral and everyone is allowed, indeed even required, to express their moral beliefs through the democratic right to vote.
Rational Secularism seeks to eradicate religion as a personal, not just political, influence, making a rational system, theory, or political party, the ultimate moral judge. Therefore the state is justified in using violence to eradicate religion and human rights as competing sources of moral influence.
Postmodern Secularism celebrates diversity, making tolerance and social inclusion the ultimate moral behaviour, creating one moral universe where tolerance is the height of morality, both political and personal. Common sense is no longer valued and democratic decision making can be legitimately overruled.