What is the difference between a hereditary monarchy and a republican system of government?

In Chicago v. Tribune Co., Thompson C.J. described in stark contrast the theories of public defamation under a hereditary monarchy and under a republican system of government. This sort of mythology may add colour and force to the exposition of American constitutional doctrine. However, political bodies can and do have reputations separate from the members of those bodies, an observation that applies to organizations of all kind. It strikes me that it is problematic to limit the legal personality of the state in this way, and it is not necessary to do so for the purposes of this case. Canada's constitutional monarchy maintains the legal differentiation between the state and its members while at the same time locating the source of political legitimacy and accountability at the ballot box. [page591]