In this methodological study we develop the foundations of measure theory using lattices as prime structures instead of rings. Topological as well as abstract regularity is incorporated into this approach from the outset. The use of inner and outer measures is replaced by transfinite constructions. Basic extension steps are transfinitely iterated to yield generalizations of Carathéodory's theorem which are optimal with respect to inner and outer approximations.
Mathematics Subject Classification (2000). 28A12, 28C20, 06B99.