Is there a connection between frodo and sauron?

[Secret Fire]

Just my unenlightened opinion, but I believe that two foils would have to interact with each other. In the book we never see these two even meet, and I question the nature of their relationship (since they have none!) as being that of each other's foil.

Actually, it is not necessary for two characters to interact in order to be a foil for eachother. Simply the fact ahtt they are in the same work is enough.