This article develops systems theory that relates the functions of leadership to shared identity and ethics. Using complex system leadership theory wherein leadership is defined as changing the rules governing local interactions, the theory links shared identity and ethics to those local rules. Collective identity is defined as a mechanism to actualise a shared set of local rules, and an ethical system is defined to be one which enables individuals to experience autonomy in the context of those rules while exhibiting transparency with regards the benefits and risks of participation. Because leadership impacts collective identity and thus the rules of interaction, and sometimes does so opaquely, creating and maintaining such a system is an ethical challenge for leadership. Unifying leadership is defined as the organisation level function that unites the system by shaping identity while defining and enforcing the ethical framework wherein individuals make informed autonomous choices.