A Tentative Completion of Quantum Mechanics

We review a proposal of how to complete non-relativistic Quantum Mechanics to a physically meaningful, mathematically precise and logically coherent theory. This proposal has been dubbed ETH-Approach to Quantum Mechanics, “E” standing for “Events,” “T” for “Trees,” and “H” for “Histories.” The ETH-Approach supplies the last one of three pillars Quantum Mechanics can be constructed upon in such a way that its foundations are solid and stable. Two of these pillars are well known. The third one has been proposed quite recently; it implies a general non-linear stochastic law for the time-evolution of states of individual physical systems.