Its a valid argument, the idea with element bending going into detail with metal and blood bending, its not surprising people would come to question what else could be shifted through your chosen element. From what I've seen the idea to bend anything relating to the main element etc is a bit sketchy, many debates have been made on the site regarding many alterations of the core element bending much like you are suggesting now, and would come down to two arguments really. Is it skill? Or majority?

Now one could say like with blood bending water is in the blood thus is can be controlled as we all know, so as you suggest why cant such things relating to other elements be controlled also? To the point, one way to solve this is by simply calculating ones skill as a elemental bender. Over time people can become masters of their element or exell for numerous reasons. Toph for example could be able to bend Metal for the reason that she can see where the earth is inside the metal via her mind mapping, or it could be the fact she is just a really good earth bender.

Majority could be another factor, it seems things that have been sub-categorised like blood and metal and even lighting seem to be in mass or of a great connection to what they are contained in, water in blood as an obvious as alot of it contained in the blood system, earth in metal regarding majority is questionable though still there is always quite a mass.

You could throw back and forth the ideas of different things that could be controlled through the core elements though all in all it resides with whether you could do it, may it be possible you could only find out through practice of your own. Though from one side I would answer that with yes, though you would have to be very skilled to say the least. Though another argument could be that such things could overpower when looking at how it would be placed into the RP. Can you imagine a Fire bender just running around combusting everyone with a click of a finger?

Its a very interesting suggestion, and if you wish to take any of this further I advise you pick away at what you would deem most usable and place it in the RP debates, as I have said you are not the first to look into what could be used.

Oh, the old Earthbending debate. Before I get to that, I'd like to clear something up about Bloodbending.

Bloodbending is the ability to manipulate the significant amount of water in the body and, as we all know, the human body is over half water. If you notice when Hama is Bloodbending, the movements of the people she controls are jerky; this implies that Bloodbenders (even ones as accomplished as Hama) don't have a fine control over the skill, especially since they can use it only during a full moon. The ample amount of water in the blood (~90%) helps to aid the Bloodbender in controlling their victim, but I think fine-tuned control would take a lifetime since the full moon is only around once a month (and even then, for a few hours).

Now, it's debateable as to what Earthbending exactly is. Take me and Toph, for example. Toph does think that Earthbenders bend minerals, but I believe that it's the use of seismic energy to manipulate earth and earthen materials. I lean more towards the seismic energy theory because Toph uses her bending as sonar; in fitting in with my theory, she uses seismic energy, then picks up what comes back to her. It would make sense that she could "see" the earthen impurities in the metal they would register just like any rock or dirt particle.

I disagree with the "Bloodbending explains why Waterbenders can heal," mainly because of the element of chi introduced with Ty Lee. When a bender bends (to my understanding), depending on what discipline they practice, either manipulate the chi of their element or use their own chi to create it. In the case of Waterbenders, they're much more adept at guiding chi through their own bodies, which would explain why they're able to heal: they use their bending to alter the chi pathways in the body of another person, and the effects of this manifest themselves physically.

Now, for Firebending and Airbending. Although we know that Firebenders can siphon heat from something, it is unknown whether they can actually transfer heat from their own body to that of another person. As for Airbenders being able to suck the air from someone's lungs, I don't know how feasible that would be, although there'd have to be some in-depth discussion as to how that works, especially since we never learn anything about Airbending aside from what we've seen Aang do. The whole breathing underwater thing is a bit iffy as well, considering that the Airbender would be limited in their oxygen supply. It would be more feasible for (as we've seen in the show) a Waterbender to bend a bubble around their body.

It's unfortunate that none of this was elaborated on in the show, but speculation is fun!

Those are all interesting points, but I'd be willing to argue that it's seismic energy that Earth Benders control only because if it was seismic then they shouldn't be limited by a lack of earth. They should be able to generate those seismic waves anywhere. And Toph in the show is specifically manipulating the "Earth impurities in the metal" which to me implies she has to manipulate the mineral. If we go by that thought process then bone bending would be possible due to the large amount of calcium that makes up the bones. That's not to say it would be easy at all, just that it's possible.

Body Bending was just a thought that had popped into my head because of blood bending. It seems to me that the human body is composed of everything needed to do one form of bending or the other. Water, Earth (via minerals), Air (Oxygen, Nitrogen, etc.), and Fire (body heat). Which I guess makes a lot of sense since earlier cultures believed the human body was only composed of those four elements... Since all the necessary elements are there for bending I guess it could be possible but I think it would take an extreme level of skill.

I like this thread! I want to hear more from you guys!

You'd think so, but with no earth to bend (as I'm assuming the way Earthbenders bend is akin to interacting with chi the way Waterbenders do) would mean they would do nothing. I illustrate this with the episode where Aang "rescued" Bumi from Omashu: he was able to bend using just his nose, even though he wasn't in contact with the earth.

I also disagree because it was through this seismic sonar that Toph was able to "see" the earthen impurities in the metal and, as there were a lot, would make metal as easy to bend for her as earth.

Hey guys this is my first debate.

There is 4 MAIN elements. Water,Fire,Earth,Air.
I would like to point out that there is many things that is not mentioned. Sand bending, as you know when toph was in the desert she could only move very little sand. The sand also acts very similar to air bending since they used the power to move their sand gliders. It also has very similar tendency's to water bending so woudn't that make it like a amalgam of the three.Ice Bending is also differnt it is basically water bending but it also has slight airbending tendencys in it like breathing on it to turn it into ice.Metal bending. Toph is beding the inpurities in the metal so she doesn't have as much controll over it like regular earth so she can just about just well bend it litterly.

Kai-

I'll concede the seismic waves theory, but only on the grounds that she still could only bend the metal by using the mineral impurities. If those impurities weren't there I don't think she could bend it. Obviously we don't know what type of metal they use in the world of Avatar but my money is on iron given the tech level, which means the mineral impurities are a lot higher than, say, steel. I think the less impurities in the metal the harder it would be to Earth Bend it whereas the more impurities the easier it gets because there is more mineral or "earth" to manipulate.

Off of the Earth Bending topic for a moment, another thought occurs... exactly what classification does "water" get. Is it any liquid with some kind of water portion to it? How much water needs to be in the liquid for it to be manipulated or how little before the Water Bender can't affect it anymore? Could a master Water Bender manipulate a thick stew for example. It sounds silly but think of the implications. Most stews, the base is a lot of water. Could a Water Bender manipulate it if it were really thick or would the water content be too little? And if they CAN bend thick liquids, just how far can they take it?

Hoenn-

A follow up to your post. Sand Bending, Ice Bending, etc. Those are all just derivitives of the elements. They are not a separate type of bending despite the name. An Earth Bender, Toph for example, can bend sand just like harder earth because it's still that same element. Sand Benders can bend regular earth as well, they just don't because it's not very practical.

Ice bending is still just Water Bending... though I have to suspend my disbelief a little bit more to think that they have the ability to generate enough cold from their bodies to freeze the water... but given that we have people flinging fire and hurling boulders at each other, I can accept the ice bending. A Water Bender can manipulate ice, or vapor even in the case of clouds, because at it's core it is still the element of water.

One thing this line of thinking does bring up is the question of inbetween substances such as magma. In the case of magma, who controls it: Fire Benders or Earth Benders? Magma/lava is molten rock, which is essentially rock melted down to a superheated substance so there is the fire element, but again... it is ROCK melted to a superheated substance so it has the earth element as well. Personally, I'm not sure.

@ Ju-Long Liu:

With regard to the ice-bending, remember that cold is not the opposite of heat - only its absence. Thus, rather than putting "cold" into the water, they're taking heat out of it. I posted an little essay covering my opinions on how the different forms of bending work a while back, in which I theorized that Waterbenders move water around by directing the latent kinetic energy present in any body of water (the liquid always swirls around on its own a little) in order to produce a force, similar to how you align the grains in a piece of iron to turn it into a magnet. In the case of ice, they would just be quelling that latent energy and forcing it to disperse - thus, bending ice is a little trickier than plain water, but just as easy to throw around.

As for magma, earthbenders would definitely be able to control it, since magma is just liquid rock. It's much the same as a waterbender moving ice - same element, just a different state (as one of the Avatars does in Aang's flashback in The Avatar State. In fact, it's not clear which bending technique is being used; one would assume fire, but I suspect there was more earthbending involved than you might think - but more on that later.

Now onto the body bending - again, my own personal theories are at odds. Rather than seismic energy, I think earthbenders use the "crystallised" energy that gets trapped in the rocks during their formation. Sedimentary rocks are compressed organic matter, and so have residual life energy in them. Igneous and metamorphic rocks are formed under extreme heat, and so have residual heat energy infused in them when they cool. (You'd think the rocks would be out of energy by now, but consider the fact that the concrete in the Hoover Dam is still curing 80 years later, and it doesn't seem too crazy) Earthbenders then use this trapped energy to shift the rocks - hence, sand and mud are bendable, just harder to control because they're not solid. Metal, on the other hand, isn't rock - it's an almost-pure metallic element, and so has no chi.

As for moving the body... I'd say it's a similar situation to metal. The elements in the human body, though all present in earth, have been processed into a refined form, removing all the earth's natural chi. The body itself has chi, but of a different kind - namely life. And that kind of chi is the realm of the firebender.

Kyozuki-

Those are some great points on Water Bending. I hadn't even thought of it as the way you explained it. Another way to explain it is that they are simply slowing down the molecules in the water itself. It doesn't stop being water, it just moves to a solid form... hmm... I think I need to stop thinking so scientifically and more spiritually about the effects of bending on the elements.

Still, as far as the minerals being so refined in the human body, I don't think that means they COULDN'T be manipulated, just that it would be very difficult. I think that it puts it in the same category as metal bending. First off, you have to be able to sense the minerals in the body before you can even use them, then you have to be an advanced enough Earth Bender to do what you want and even that is incredibly difficult.

I don't know... I guess I just think that if the whole point of the Avatar is to maintain the balance between the four elements, having only one element that can directly impact the living body seems a little out of balance to me and not just because I'm an Earth Bender fan. It's like saying "Everyone is equal here in terms of power... except this guy! This guy is just a liiiiittle more equal than you... but it's still balanced!".

Truthfully, without an answer from the show's creators we'll never really know, so that's kind of a bummer!

In response to the Earthbending, I do agree that without the earthen impurities, Toph couldn't bend metal, but then again, it's doubtful that the Fire Nation has the technology to completely purge the metal they work of those impurities. As we don't know for sure whether the mineral theory or the seismic wave theory is true, the only thing one can say for certain is that there's earth in metal, and that's why Toph can bend it.

As for Waterbending, I believe it varies. We've seen Katara bend perfume, which would imply that a Waterbender could bend anything with water in it, but I've been developing a theory on this since I read your post. I believe it depends on the viscosity of the fluid. Things like perfume that have a low viscosity would be able to be bent as water is, considering that water makes up a majority of those compounds (hence the low viscosity). Things with a higher viscosity, like mud or stew, would be less likely to be bent because there's less water in it; however, as we saw in The Painted Lady, Waterbenders are able to separate water out of things like sludge and mud, so that might imply that the mass of the solid components of the sludge were too heavy to be carried by the water they were suspended in.