Objectivists argue about what branch of normative ethics it is.  I like to see it as a branch of Consequentialism, like a cousin of Utilitarianism, except where the utility function is not what outcome is best for the greater good, but what outcome is best for the self.  They tend to believe that what is best for the self is by definition best for everyone.<p>Debates usually get hung up on Tragedy of the Commons, and whether it actually exists as a meaningful concept or whether it can always be solved via private property ownership.