I would argue that everything man-made started out with products that were natural, and compiling one natural product on top of another still results in a natural product. Not a naturally occuring product, but a natural (as in, deriving from nature) product all the same.
It all depends on where you decide to draw the line between what is of nature and what is of man. Consider the idea of the colonial Christian encountering the primitive or natural man. Intelligence in many ways, and the constructs of society are the antithesis of nature. Try finding 1 square foot of natural space in any city.
After a while, if you are guided by the definition that you provided, the original nature of the item considered has been removed so many times that it is no longer viable any longer. I tend to believe that once the intelligence of man has taken a material out of it’s naturally occuring element it is no longer of nature, and so therefore no longer natural. I do see your point though, and I do think one could argue succesfully from either point of view.
I was just coming back to edit it to say something to the effect that the christian man is not natural, instead of christianity does not think man is natural, but I see you beat me to it.
Regardless, Christianity judges man in a natural state to be without the knowledge of god. And so again I state that I believe intelligence makes man unnatural.
Christianity is not requiring man to forgo the natural state it is requiring humans to rise above it. This in noway makes humans unnatural for rising above the natural state.
The bible is saying that the natural state is man’s origin. Man is to go past what he began as . This does not in any way imply intelligence is unnatural. It only makes it a step in man’s evolution, which is very natural as all things evolve even Gods. The bible is only asking man to evolve.
While I would agree with you that the universe is somewhat uncaring, a fact I believe is the drawback of one of God’s greatest gifts to us, free will, it is not unnatural to construct elements of civilization that exist in harmony to nature. In fact, if one reviews their history, they will find that until man began to depend on technology, society, economy, agriculture, and all of the things that make up civilization were still dependant on the natural world. Therefore, while not everything man has constructed to this day is natural, civilization, in and of itself, is a natural extension of group dynamics in primitive man.