We had a discussion at dinner tonight about religion and government. Why should one want to keep church and state separate? It's taken as such an axiom that we don't hear much of a discussion about why it's important.
My theory—which now that I'm coming to write it down will probably sound pretty simple-minded—is that we want to keep religion out of government because we don't want the government telling us what to believe. In some basic way it seems to me to be as simple as that. Government celebrations of religious holidays, for example, or government sponsored prayers at public events tell people that those prayers or holidays celebrate a way of looking at the world that the government supports. One is forced either to accept that perspective or to acknowledge that one is out of step with how the government is saying the world is.
Government should not be supporting metaphysical and theological positions—or at least those who want to keep government and religion separate argue that government should not be making these kinds of assertions.
But what about public education? Isn't that government telling us what to believe? It probably is, and if one were consistent about wanting to keep government out of our heads, I'm not sure how one would justify government run education.
Debora suggests that a distinction can be made between belief and knowledge. It's ok for the government to teach people arithmetic, for example. This generalizes to the position that it's ok for the government to teach the fruits of secular investigation, such as science, history, etc. In some (perhaps many) cases, it may be difficult to draw the line between secular investigation and sectarian beliefs.
As Debora again pointed out, among the most difficult areas would be the teaching of values like honesty, good citizenship, and patriotism. Do we want the government to be teaching those beliefs?