Well... I have been reading this with somewhat of a scholarly interest... but not for the reasons that you might think.
It's fascinating how sometimes the group you agree with has the worst arguments.
For example...
Phlogistician, Stryder, Bells.. etc.
Your arguments are bigoted and stupid. Seriously.
It tends to boil down to this kind of argument...
Q "Why is this wrong"
A "You are sick"
Q "Why?"
A "Cause it's wrong"
Q "Why is it wrong"
A "Cause you're sick"
Nice way to make his point for him folks.
Let's look at the question again in a logical sense shall we?
ancientregime
Your argument largely bases itself on a sliding scale, which makes for a poor quality argument. Let me give you an example.
Reductio Ad Absurdem
You state...
Now, if we take it a step further, imagine a person who walks upon a situation where they see an aesthetically attractive person by their point of view, and this person happens to be a pre-pubescent human masturbating, would it be abnormal not to be turned on?
What you have done however is to take a vague notion of age rather than be specific.
How about if the attractive young person was 5?
How about 1?
How about a fetus?
You can see that there is a point at which we can say.. that is no longer sexually appropriate.
One problem with this whole argument line is that there are people who will find a block of wood attractive. People have had sex with tables, animals, rubber ducks.. etc.
However.. that is still beside the point.
Harm
You fail to see where the harm comes in.
One of the reasons for the laws against child porn is to do with harm. Harm comes when a child is forced to do sexual acts against his or her will ... amongst other examples.
Now.. if a man has sexual desires towards something and never acts on it... no harm done.
However, that is not how things happen in the real world.
One man makes a drawing of a naked child. No harm done.
One man purchases said drawing. No harm done.
Another man sees a market for those drawings.
More are sold.
Other men see the potential for better profit if you get real children in there.
That is where the harm becomes real.
You can always say that it won't escalate to that. However, we all know it will.
That is one of the reasons why that sort of thing is illegal and should stay thus.
Do you need more?