I am beginning to think the Libertarian philosophy contrasting the coercive nature of the state with the voluntary, mutually beneficial associations inherent in free-market [crony-free ] capitalism began with Bastiat's Economic Harmonies. Everything that I once thought was original with Ayn Rand is there, in a more bright and crisp form--with a more affable demeanor, though with equal persuasive power.
Note: When reading Bastiat you must remember externalities were not an issue in his time, and the reader must guess how he would write today.