Natural = Good ?
Some well-intentioned people create arguments by equating the concept of natural with the concept of good. I say they are well-intentioned because it is by no means done out of malice or prospects of winning debate points. However, the equation is not valid. In fact, within philosophical circles it is known as the 'appeal to nature' fallacy.
The first problem we have is that it is unclear what 'natural' really means.