This book addresses Hilbert's sixth problem — the axiomatisation of physics — directly and systematically. It presents Quantum-Geometry Dynamics (QGD), a physical theory derived from a minimal axiom set in which space is discrete, matter is constituted by fundamental kinetic particles called preons(+), and all physical change is governed by two opposing forces: p-gravity, the attractive force between preons(+), and n-gravity, the repulsive force between the fundamental spatial constituents, preons(−), whose mutual repulsion dimensionalises discrete quantum-geometrical space. From these axioms, without additional assumptions, QGD derives the full range of physical phenomena described by quantum mechanics, special and general relativity, and the Standard Model — while making novel predictions that distinguish it empirically from all three. The foundational argument of the book is that existing physical theories — quantum mechanics, general relativity, and the Standard Model — are non-minimal frameworks. They introduce primitives that are not derivable from a minimal axiom set: the continuous wave function, continuous spacetime, probabilistic measurement, multiple fundamental particles, and numerous free parameters. Their persistent incompatibilities — above all the quantum gravity problem — are not deep facts about nature but structural consequences of their non-minimality. A theory derived from a genuinely minimal axiom set does not divide nature into a quantum sector and a gr