Alright so the last episode made me consider the role between the Hostiles and the Others. And this is along the lines of what I am thinking...

The Others are the initiative on the island for their research and all that. Maybe they have bigger roles/ideals...who knows.

But I think the Hostiles, whom live on the island, may somehow be ghosts...since most of the legitimate hostiles we see are dead or otherwise spiritlike. And people are always seeing visions of people outside the Others' camps. Perhaps it is some sort of place for unresting spirits. And basically the Others don't like being haunted. I'll go into more depth maybe, but I figure I'll open it for discussion now.

I think the term "Hostiles" is Dharma's name for the other inhabitants of the island. The Losties call them "Others". Basically the two terms are interchangable, the only difference I see is that the present day Others also have recruits from outside among them, they are not all native Crapholies now.