Unified Architectural Theory: Form, Language, Complexity. A Companion to Christopher Alexander\'s The Phenomenon of Life -- The Nature of Order, Book 1. With contributions by Christopher Alexander, Zaheer Allam, Michael Carey, Peter Eisenman, Leon Krier, Kenneth G., Masden II, Michael W. Mehaffy, and Edward O. Wilson. We are at the beginning of a new method of understanding, studying, and practicing architecture. We seek solutions by fusing timeless truths with cutting-edge scientific findings as we get ready to give up design based on frequently irrelevant pictures in favor of a more meaningful paradigm. These clarify the ability of architecture to reconnect with nature. Through the discovery of lost architectural languages, Unified Architectural Theory reinvents architecture. Organized in 44 sections, this book contains lecture notes and readings from a course based on Christopher Alexander\\\\'s The Nature of Order, Book 1, and using Salingaros\\\\' A Theory of Architecture.