[Antoninus]

Child pornography is illegal because it can't be made with knowledgeable consent. That is hardly and artificial difference.

How does someone miraculously attain "knowledgeable consent" one second after midnight of their 18th birthday? And here I thought the pro-porn crowd didn't believe in miracles?

This is the very definition of "artificial difference."

[Durus]

First you argue that the government can, without fail, tell me and everyone else what is and is not good for us to read, view, and listen to and then you tell me that they can't even accuratly determine the age of majority?

18 was the number chosen for various logical and illogical reason. Unless you plan on proposing some sort of required test to determine majority I suggest that 18 is as good a age as any.