You're full of s**t, but you're not stupid

In every culture and many households, there are words which are considered taboo. What exactly is a bad word? In some households, using exclamations such as "Oh my god!" or "Jesus Christ!" would be unthinkable. In others, you can't say pee pee. Because you have to call it something, cute ways are found to use the same word—wee wee.

In my home growing up, swearing was by no means encouraged. There was one word we were absolutely forbidden to say to anyone—stupid. In my family, calling anyone stupid was worse than telling them to go to hell. In high school, I did find a way around this using my sense of humor along with some medical terminology. I once told my younger sister that the doctor called to schedule her annual pneumoencelphalectomy. She then asked me to spell it so she could look it up! If you know medical terminology, you will be able to figure out I was cleverly calling her an airhead. How come I can say poo and crap, but not shit? Do they not mean the same thing? Perhaps instead of saying, "You're full of shit", I should say, "You full of excrement". Personally, I think the former makes the point a bit better, don't you?

Why is intercourse okay, but fucking is equivalent to a bomb? "I want to fuck you" sounds much better than "I'd like to have intercourse with you". The guy who said the former is the one I'd pick. Isn't an explosive climax better than ending it by conversing with each other?

Vagina is okay, but not pussy. If pussy meant vagina in French, would it still be a bad word?

Are these laid out in the Bible? The Koran?

What or who determines which words are acceptable and which are not?

Seriously, words are not inherently evil. Please, if you're the one who determines which words are okay, and which are not, please enlighten me as to the determining formula.

An inquiring mind wants to know—word police, clue me in!