Never mind. It was poorly worded, but I misinterpreted the intent.
I would say, rather, that, while society might actually be better if some forms of expression were removed, society would be much, much worse off if the instrument of removal were to exist. If censors actually had power, if bluestockings and bowdlers had their way, if commissions came into existence, if expression itself were inspected, regulated, and controlled.
It may be a slippery slope argument, but the power to ban porn implies the power to ban humor, satire, caricature, or commentary. Who the hell can we trust to stand between us and what we would read?
We could, as a society, afford to lose porn. We cannot afford to institute a policy of imprimatur upon our information content.
Have I ever mentioned how much I like you? 
It’s all fun and games until some guy gets his rocks off to cartoon porn.
Of course not. Sexual self-expression is essential to most humans’ health.
Porn is not necessary to sexual self-expression. If porn ceased to exist, sexuality would be hampered to a certain degree, but not to the point of causing an epidemic of mental health issues.
(Also, porn could cease to exist without erotica ceasing to exist. But that’s only a minor quibble.)
(And, lest anyone is foolish enough to imagine it, I am not arguing that porn should cease to exist. It’s like any other genre – horror, romance, historical fiction, science fiction: the world would be very, very little worse off if it had never existed in the first place, and, frankly, little worse off if it suddenly ceased to exist. Look at all the genres of fiction which have ceased to exist, at least in terms of meaningful popularity. Look at how genres change. Heck, look at how porn has changed!)
I think you have a definition for ‘porn’ that is at odds with what most people define it as.
Possible… I had always thought it ran mostly along the lines of “penetration” images. Thus, Hustler, Porn; Playboy, erotica.
I would certainly reject any definition that classed any visual image of a breast or a nipple as “Porn.” Way too inclusive.
None of this is really too relevant to my sub-point – that if porn went away, the world would be but little impoverished – and that sub-point is not altogether relevant to my main point – agreeing with a rejection of the premise of the OP.
So… Never mind, and carry on!
(Hustler? Playboy? May open a poll…)
We very recently had a poll on whether or not playboy was considered porn, and I think most posters agreed it was considered “softcore” porn. It’s certainly not art.
Playboy? Not art? “Certainly” not art? Wow, I cannot agree with that! I would say that Playboy photography is very highly artistic, some of the finest photographic art ever published.
There’s no reason why something can’t be porn and art at the same time. Especially when it’s drawn porn, which comes from the mind of a human creator and not a camera. Saying that it can’t be art is just a way of caving into the “porn is evil” dogma and sneering at it.
Let me clarify by saying that it’s certainly not art, to me. But I’m a gay man and rarely ever subject myself to Playboy magazines so I am probably not the greatest critic.
I think it’s quite possible for porn to be artistic, and to make good porn is a type of artform… if that makes any sense.
If it can’t be porn and art at the same time, Taschen Publishing has got a lot of “artbooks” the bookstores will have to move from one shelf to another…
But back to the worthiness of defending art or porn or entertainment that’s vulgar and offensive and that society could function just as well without, I’ll just throw this one out: think about it substituting “cartoon porn” with “cartoons of Muhammad”.
Oh, and I missed this:
You do understand that exists, don’t you? 
As I see it, there are three reasons to outlaw child pornography (not mutually exclusive):
[ol]
[li]To punish people for having those thoughts[/li][li]To make it clear That Sort of Thing is not ok[/li][li]To eliminate (or minimize) the market for industrial-scale chile abuse[/li][/ol]
The last – the only one I endorse – doesn’t require outlawing porn that doesn’t depict actual children (though I can live with edge cases having the burden on the producer to demonstrate that it doesn’t involve actual children). So cartoons, written, etc. can all be legal.
Number 1 scares me a little, for reasons a community like SDMB should appreciate.
How in the world would a producer ever be able to prove that their drawings weren’t based on a real child???
Why am I laughing while imagining a production line of children and abusers?
While I’m not fond of burden-of-proof being on the accused in any case, my thought was that **Hershele Ostropoler ** meant that they would have to show that they were using Photoshop or a rendering program.
Drawings aren’t edge cases. I was thinking of e.g., a photograph of someone who looks quite convincingly 16.
Alas, in the case of outright obscenity, PROTECT Act tries to make it irrelevant if a real child was used, that part is yet to be tested all the way up the system AFAIK.
As for live actors who LOOK underage, that’s an entire other realm and they are protected as long as their papers are in order. Case from my local US District!
Notice though how there was no attempt to prosecute for simple “obscenity” - the “community standard” criterion becomes tautological in that the jury could have* subjectively* deemed the exact same video as obscene if she had indeed been underage, but would not do so knowing she was an adult.
I honestly don’t know where I stand in this case, but that’s not to say I don’t watch manga porn. I don’t see it as hurting anyone. I do have a question though, I’ve noticed that whenever I do search up manga porn, straight away there’s a notification saying that this has been reported for abuse and I assume is because there probably was a picture of a minor shown procatively cartoonic. Is this notification something to indicate that you’ve been reported and face charges?