What is "natural"?

Same as cloning piggies and cows, surrogacy and freezing of sperms/eggs are often questioned, or rather accused as "unnatural."

It has a lot to do with our spiritual concern that "things are supposed to happen just the way they do." But when it comes to "natural" or "normal," where should we draw that line?

We change our hairdo, fake our hair color, and put make-ups. We know how to treat a disease, by taking medications and procedures. Abortion has always been discussed as a controversial issue. Should we stop or keep going ?

And most of the all, we wouldn't be such civilized human kinds if we were satisfied the world we had. Some may fear we are reaching the point where god stands, or destroying ourselves with civilization.

The most scary thing is, there is no referee.