sarcina

I guess what I'm looking for is the single branch or sub-branch of study that cradles the very edge between philosophy and mathematics -- if it even exists. Part of my confusion stems from the wide range of sub-disciplines (ie. Predicate Calculus encompasses first-order logic, second order logic, etc).

Hi, Over the course of the last few weeks I've been attempting to learn about the foundations of mathematics and yet I've been unable to find out what the single most fundamental branch of mathematics is. I've read a few books that covered mathematical logic, mathematical philosophy, and elementry set theory, and yet the answer still eludes me. Could someone please point me in the right direction and tell me what the single most fundamental branch of mathematics is, and what branch of logic does the whole of mathematics stem from? Any help would be very much appreciated. Edit: Clarified question