In the Eigen Theory of the physical world, the fundamental form of a particle of matter is a distribution of points that forms a manifold of its own. Each point results from the intersection of a corresponding pair of eigenvelocity vectors, which are functions of a pair of symmetric and antisymmetric tensors characteristic of gravitation and electromagnetism respectively. The theory develops in three stages. The first and second stages produce the wave and particle aspects matter. The third stage formulates the base manifold, characterised by an eigenfield of a second pair of symmetric and antisymmetric tensors, in which the particle moves as a whole but with only the particle centre remaining in contact with it. The first two stages expose the reality behind matter-antimatter, the quantum mechanical wave-particle duality and the results of the double-slit experiment. The third stage reveals the nature of dark energy and the structure of dark matter. In Eigen Theory Quantum Mechanics becomes restructured; in particular the uncertainty principle ceases to exist.