"Man is a social animal. Recognizing natural rights and not initiating force is the only rational way for men to coexist."
But isn't that just another way of saying that "natural rights" are really just a social construct? But I agree that it is the only rational basis on which to build a society - but man, as often as not, is not a rational being.
You're getting into the would "man in a state of nature" have or need rights argument. Good question but I'm too tired to head that way.
...man, as often as not, is not a rational being.
That coupled with man's apparently natural lust for power and posessions is the root of our problem. Can't forget laziness. As A.J. Nock pointed out there are two ways to make a living: (1) the economic means (working for what you have) and (2) the political means (taking from others what they have earned). The state is a parasite.