Book excerpt: In this expanded edition of Quanta, Logic and Spacetime, the logical base is greatly broadened and quantum-computational aspects of the approach are brought to the fore. The first two parts of this edition may indeed be regarded as providing a self-contained and logic-based foundation for OCo and an introduction to OCo the enterprise known as quantum computing. The rest of the work takes on the task (as in the first edition) of computing from first principles certain dynamical expressions which turn out to compare favorably with the Lagrangian densities of the (massless) Standard Model, including gravity. The logic of this process is now subject to greater formal rigor than was possible in the first edition, and the central thesis OCo that quantum physics at a fundamental level may itself be realized as a species of quantum computation OCo is strongly underscored. Errata. Errata (159 KB). Sample Chapter(s). Foundations (207 KB). Contents: Preliminaries: Foundations: Quantum Sets; Group Duality, Coherence and Cyclic Actions; Computational Paradigms: Natural Deduction; Quantum Logic; The Computational Resources of Quantum Logic; The Plenum: A Quantum Net; Towards a Correspondence Principle for the Quantum Net; A Correspondence Principle for the Quantum Net; Dynamics I; Dynamics II; Comparisons, Interpretations and Speculations. Readership: Mathematicians and physicists."