The study of hierarchical power imposes a function-based approach, as it is deeply linked to the theory of public personality and to the arrangement of habilitations or jurisdictions in administrative structures. This preamble allows to identity its proper characteristics and to define it as a mean to unify the will of public persons. On a theoretical point of view, it is an unconditioned power concerning the whole activity of subordinates, as they can edict legal acts or realise physical operations. Through the diverse privileges of instruction, correction and substitution, each of which constitutes a particular aspect, it allows superiors to command and control. However and beyond these instruments, hierarchical power has a true unity which results of its particular function. This doesn’t implies that it is not subject to variation by virtue of respective empowerment of superior and subordinate members of the Administration, for example as a consequence of devolution or delegation of power that can modify some of its expressions. Contrariwise, it is sometimes the alteration of hierarchical power that reveals a particular arrangement of habilitations. Moreover, consideration should be given to hierarchical power beyond the relationship between superior and subordinate. As it shows specificities and needs the adjunction of non hierarchical powers that guarantees its effectiveness, hierarchical power also plays a role, in law and in fact, in respect of the governed or constituents, which puts the distinction sometimes made between internal and external law into perspective.
