Right, I understand that, but it's a bit like saying "I want to use C, but not the standard C library." The Foundation framework is the basic equivalent of the C library, without it, you can't do anything.
No, it's not. The standard C library is specified by the C language specification. Foundation is not specified by the objC language specification, it's specified by NextStep. It's more like saying "I want to use C, but not glib".