As we gear up for a 3-unit FA elective, the question arises as to what ought to be taught in the five three-hour class sessions. The history of the world is encompassed in the doctrine covered by the First Amendment, devoted as it is to matters of belief, speech, conscience, science, religion, popular sovereignty, democracy, representative government, and a few other small topics like that.
Suppose you belonged to a religious group, really took it seriously, and found that you disagreed with something your group taught was right, true, and the Word of God. Where would that leave you? Suppose the punishment for disagreeing with the teachings of the church was burning at the stake?
What do we call a person who disagrees with the teaching of his church?
A heretic.
Suppose you had no place to go? You were caught teaching wrong doctrine, as Galileo was. Imagine teaching that the Earth revolved around the Sun. How silly! Hang him. It could be worth your life to make a discovery that contradicted the teaching of the church. Not for nothing did Copernicus keep secret his finding that the Earth revolved around the Sun when the church taught the opposite. The church was in control. People did get burned at the stake.
So I looked up heresy and found the Wikipedia entry, here.
The stakes can be high when you enter First Amendment territory.