Missionaries are evil
Missionaries.
You know, the people who go out to backwater societies bearing bibles determined to bring the heathens into god's fold, and who only know how to have sex in one position?
I think they have a lot to answer for.
Firstly, and most obviously, not being a christian, I don't see much virtue in going trying to convince people to believe in christianity.
But secondly, I'm not even sure they are doing anything good.
I've heard that missionaries believe or claim that they are doing good things beyond the spreading of god's word. They are educating the heathens, convincing them not to kill each other, and providing them with clothing and shoes, because the poor things were running around like half-naked savages before.
But I suspect the reality was somewhat different in many cases.
First, there was the unintentional bringing of diseases to which the 'natives' had no immunity, thereby killing them. OK, that's really not the missionaries fault - they didn't know.
Then there's the education. You've got to remember that the 'natives' had lived wherever it is sucessfully for thousands of years. In Papua New Guinea, people had sucessfully survived in the highlands for 40,000 years. They obviously knew a thing or two about how to do it.
But then the missionaries come along and tell them how ignorant they are, and start teaching them western stuff. Sure, that might be useful if they were going to live in a western society, but many of them aren't. All the missionary education got them were useless, irrelevant, or even wrong ideas.
For instance, the more enlightened westerners told the new guineans that they were doing their agriculture wrong. Their irrigation was wrong, they crop rotation was wrong etc, and so they educated the young people and convinced them to change their ways. Of course it was a disaster.
You don't survive as a society for 40,000 years without figuring out how to most productively feed everyone. European ways work well in europe, but they don't translate - the pngers know best how to grow crops in png.
One of the key problems a society has over time is making sure the population doesn't outstrip their agricultures ability to feed it. Obviously, step 1 is to expand your agriculture as much as you can, and try to make it more productive. But that possibility is finite. There is some maximum limit, even with small innovations. You still have to make sure you don't produce more people than can be sustained.
Old societies had all sorts of methods for doing this. Contraception - herbal and via coitus interruptus, abortion, infanticide, suicide, non-procreation by some members of society, tribal warfare, and sending 'surplus' people on dangerous quests. However, the missionaries managed to convince lots of people that they would burn forever in the fiery pits of hell if they did any of these things.
Hence, most discovered civilisations who were converted by missionaries had a double whammy. Their populations exploded because of not practicing contraception & abortion etc, and their ability to produce food declined because of poorer agricultral practices introduced by the missionaries, and the younger members of society losing the older ways due to their missionary education.
And this doesn't even touch on the most dispicable thing, in my view. One missionary in png bragged to Jared Diamond about how he told his newly converted congregation that they had to prove their faith in the christian god by collecting up all their 'pagan' artifacts (i.e. their cultural heritage) and burning them.
The spanish conquistadors in central america set about systematically burning all the Mayan books, since they were pagan, and weren't the bible, they obviously must be words of the devil. Only four survived.