"That simply doesn't happen in mainstream usage."

Well, if we're talking mainstream usage, between the amount of cigarettes vs. the amount of joints people smoke, cigarattes are much higher. They're both bad for you. The difference between them is negligable, as far as I'm concerned.

"I know that there has not yet been a proven link, hence my use of the word "correlation"."

Then you should look up the meaning of correlation. There is not a proven correlation. Meaning the experiments that have been done are either inconclusive, or not scientifically valid. This means they could've done literally anything to skew the results.

"People who smoke dope are more likely to get those disorders."

No. A few people who smoked dope had a higher chance of getting them than a few who didn't. That means NOTHING. It could be pure luck. I won't argue this further, because it's just not valid. If I smoke and my friend doesn't, and I get AIDS, is that a correlation? Of course not.

"I prefer research and studies that are conducted in an objective manner, rather than beginning with a presumption and trying to find facts that fit it."

You seem pretty biased against marijuana, just from reading your post.

And to your first post:

I think how harmful they are is irrelevant. If you're going to argue that, there's a hell of a lot of other things you should be up in arms against (like say, industrialization in general, and cars? Way more harmful chemicals than cigarettes).

Usage should be an entirely personal issue. If we can choose to damage ourselves with alcohol, why not anything else? Where do we draw the line? Why?

If you're for illegalizing all drugs (alcohol & cigarettes), why not caffiene? Just because it's usually done in small amounts? Why not other things that are disorienting and possibly harmful, like rollarcoasters? Again, where's the line drawn?

"The argument that "one is legal so the other one should be" doesn't hold water, either."

Of course it does. If one form is legal, the other should be too. All theft is illegal, not just theft on children or whatever. That's how laws work. The fact that you can use the same argument to say all drugs should be legal is completely irrelevant.