A combination of the subjection theory and the subject theory arguably provides a workable distinction. Under this approach, a field of law is considered public law where one actor is a public authority endowed with the power to act unilaterally ("imperium") and this actor uses that "imperium" in the particular relationship. In other words, all depends whether the public authority is acting as a public or a private entity, say when ordering office supplies. This latest theory considers public law a special instance.