Canadian Politics Today

Depends. If you're teaching Math, Science, History, Geography and English, you're teaching facts which can't be contradicted.
You can teach global warming in such a way. There are certain facts which cannot be contradicted about global warming/climate change, so you can teach it, provided you stick with that. If you add in information which is mere supposition and which can be intelligently and logically contradicted, but state otherwise, then that is indoctrination.

I would say if you 'teach' something with an attitude which says "This may not be disagreed with, altered or contradicted" and it CAN be disagreed with, altered or contradicted in some manner, then you're indoctrinating. And I don't mean contradicted in the way loons disagree with 9/11.

Because it's so clearly a part of morality, and part of the reason this topic arose, let's look at sexuality, and how it is taught in schools. If you're teaching the physical processes of sexuality you cann't be contradicted for they are all fact. However, schools also teach sex and sexuality from a moral perspective which often contradicts the moral teachings  of churches, mosques and temples. The new curriculum (and I had to go reading about this since I don't really care that much) introduces sex ed in grade three. That's a hell of a lot younger than we got it, which I believe was grade six. And the first thing they start off with is 'the diversity of gender identity and sexual orientation". This is probably the basis of most of the complaints since most churches, temples and mosques consider male-female sex within marriage to be the only morally acceptable choice. The question then becomes, who has a right to be teaching these kids sexual morality, the schools or their parents and religious groups? And also, is teaching it as fact, at the age of eight, too young? Ie, are these kids too young to question or are they simply sponges for whatever they're told.

You can't "teach" somebody not to be gay for instance, if they in fact are. The fact it was ignored when you were in grade 6 simply drove the concept underground and likely made life more difficult for those people who didn't fit the church type molds. And I seriously doubt discussions of such issues caused anyone to change their own sexual orientation.