Federalist Paper No. 39 Answering Critics of New Constitution

How does James Madison justify the new Constitution on the “republican” nor “confederal” principles?

In Federalist Paper No. 39, Madison attempts to answer critics (such as “Brutus”) of the new Constitution who argued that it followed neither the “republican” nor “confederal” principles. How does Madison justify the new Constitution on both of these grounds? Which do you find most persuasive: Madison’s arguments or of his critics? Why?