Its 7:00, I'm still at work, and I'm reading Anandtech forums. But, I see an opportunity to utilize some off my education that I so seldomly use at work and I have to grab it.
In my civil liberties classes in college we talked about censorship at school and church and state issues.
dullard was right, free speech can be limited, and the Supreme Court has mostly held that school is a place were the absolute right to free speech does not exist. For example, the school has the ability to limit speech (to be read speech, writing, and certain actions that make statements ie wearing a WWJD? bracelet) that may be disruptive or harmful. Generally courts would side with a principal in these matters.
However, your brothers paper would be neither disruptive nor harmful (unless there was to be a presentation in front of the class).
On seperation of church or state, the Constituition is pretty clear that no law shall endorse a particular religion. The teacher reading a paper based on the bible is clearly not any type of endorsement. Besides, the whole point of this paper is probably to evaluate your brothers writing ability and his ability to contruct an arguement and defend his position in a clear manner. He could write about why it is socially acceptable to flick boogers at his classmates and as long as he devoolps a well written arguement eith support for his position he should get an A.
I did like IJump's suggestion that he should write a paper presenting evidence for or against the historical event of Noah's Ark.
Another suggestion, why not talk to the teacher, see their point of view before the paper gets turned in.
-Lykaon78