Erm, guys, explain to me what do you mean when you say that something is unnatural? How can any existing object in the universe can be considered as not a part of the universe? How can something that happens in nature (using the 'The material world and its phenomena' definition of 'nature') be defined as unnatural?
It seems to me that many people like to endue human's brain with some mystical power that can produce something, that is not a part of nature. Brain, like any other organ in your body is natural, so any products of brain, any thought, any idea, any concept should be seen as a natural thing, I think.
Unnatural... This word has no sence to me, I don't even know why it has it's place in our language.