"If it's happening on Earth right now . . . it is natural." Murder is happening right now on Earth. So, it's natural. Why try to stop or control it? It's a natural instinct in some people. Same with rape and other things most people would describe as crimes against humanity. Those judgements come from STANDARDS set by civilized people for the betterment of society. These standards are the foundation of a civilized society. Tolerance within those standards can be discussed. However, lowering the standards so that anyone can meet them is counter-productive and weakens the social structure upon which we all stand. Catholics, by the way, do not try to force their beliefs on anyone; they merely try to protect the rights awarded them.