Utopia; an imaginary island described in Sir Thomas More's Utopia (1516) as enjoying perfection in law, politics, etc.
2.an ideal place or state.
3.any visionary system of political or social perfection.
If you haven't guessed already, my theory is that The Others, want to create a 'Utopia' a city, or island of perfection. People should not be FLAWED, and the others would kill any whom are not indeed, perfect. They only want these perfect people. Proof of this theory is everywhere, from Ben's line 'I want you to want to save me' to Mikhail's 'You are not on the list because you are flawed'. Sawyer and Kate were let go perhaps because they would come back for Jack, with others who are flawed like Sayid, and 'LOCKE???'. I say 'LOCKE???' because we are yet to know what he has done wrong, although the drugs farm could perhaps be why he is flawed, and maybe the anger issues. The Black Smoke COULD be passed off as the main 'leader' of the Others (stupid I know but you get what I mean) since he killed (I say he I should say it) Eko. Jack is now living with them because he want to help people and he is supposedly a perfect man in that he had no intention to kill Ben and he helped that woman who way shot by Sun because he will help anyone. He didn't give up on the woman he married because he want to help... The list is then, those who the others want. LOADS of things can't yet be explained, but so much fits that alot can be explained by this theory.
ANY queries I will be happy to answer, just post comments and I will do my best to reply.
Theory by Steve_c32