I am pretty sure that we all agree that humans will never have a complete universal morality because we put so many things into the bucket of morality that could not be addressed by a universal morality. There are people who find it immoral marry between races so no logical system could ever resolve their specific belief. Logically though, we could propose a set of core axioms that everyone could agree on and then build up a system from the axioms. This is what Rand attempts to do so from her logical system you can at least define some moral arguments as universal.