They built their rules on astronomical observations that indicated the change of seasons and observations of cause and effect in other areas. The priests kept the records, and were the most educated members of their respective societies.

They couldn't figure out, for instance, why eating pork or seafood made one sick, but they observed that it did. So, as their analytical tools didn't include things like microscopes, they attributed the cause to a deity who declared such foods to be unclean. Well, what else could it be? And how do you make people follow rules they might be inclined to ignore, even if they improve the health of the community, without giving a reason, some reason, any reason, to adhere to them.

These rules became cast in stone, immutable because they supposedly came from God. People were criticized in the strongest possible way -- by execution or expulsion -- for questioning them. Scientific inquiry stagnates in such an environment.

I wish I remember where I read this: Religion vs. science is actually the science of 4000 BCE vs. the science of the 20th (now 21st) century CE.

It's no more arrogant to assume the latter is correct than to assume the former is.

As for Art's observation concerning religious instruction, let me share this with you:

I attended Catholic schools all my life, except for graduate school. When I was studying for my First Communion, a sacrament received at 7 years old, we had extra classes to make sure we were properly aware of our faith. One of the exercises had to do with thought problems in which one was required to reflect on the correct answer to a social problem for a Catholic. A thought problem that got me into trouble concerned what a Catholic child was to do if invited to a Jewish friend's bar mitzvah. The correct answer was not to go because Catholics were not to "mix" with other religions, as those religions were inferior. I didn't see the point of this, because to me it was not about the religion at all, but about the person, just like the stories of Jesus socializing with all kinds of people. I could get away with arguing with nuns because I had relatives highly placed in the mother house of the orders that taught in my schools, so I did. They declared me wrong, but I never admitted it. (Later, Vatican II sided with the position I had taken. I felt quite smug.) I know very well from long experience that religious instruction, as well as instruction in other subjects, like history, are altered by denominational teaching. I've seen it among other religions, looking in from the outside, as well.

It may sound disrespectful of religion to speak of it in derogatory terms, but religions speak of each other in just such terms. Art is right when he says that to teach them all side by side as an academic discipline, without the elevation of one over the rest, would give students, as citizens, quite a different perspective on what they are actually made of. It would give people an opportunity to crack off the fossilized skin of 6000-year-old science that religions wear like armor, allow the poetry and metaphor that animates spiritual awareness to breathe, and possibly put some of the Us Vs. Them violence into the grave where it belongs.