It is a bold undertaking to pick out a single pair of concepts form a closed system in order to get to the bottom of them. For the "organon" of philosophy is one, and the individual concepts that we may isolate are so intertwined that each sheds light on the others and none can be treated exhaustively outside of its context.
Such is the dilemma of all human philosophizing: truth is but one, yet for us it falls into truths (plural) that we must master step by step. At some point we must plunge in to discover a greater expanse; yet when this broader horizon does appear, a new depth will open up at our point of entry.
Edith Stein, Potency and Act, Redmond, tr. ICS Publications (Washington, DC: 2009) p. 5