Modem microelectronic technology.gives opportunities to build digital circuits of huge complexity and provides a wide diversity of logic building blocks. Although logic designers have been building circuits for many years, they have realized that advances in microelectronic technology are outstripping their abilities to make use of the created opportunities. In this paper, we present the fundamentals of a logic design methodology which meets the requirements of today's complex circuits and modem building blocks. The methodology is based on the theory of general full-decompositions which constitutes the theory of digital circuit structures at the highest abstraction level. The paper explains the theory and shows how it can be used for digital circuit synthesis. The decomposition methodology that is presented ensures "correctness by construction" and enables very effective and efficient post-factum validation. It makes possible extensive examination of the structural features of the required information processing in relation to a given set of objectives and constraints.