PFUSRC-055B The Entropy of Civilization and the Third Threshold: From Saturation of the Second Threshold to the Necessity of Dimensional Ascent

PFUSRC-055 elaborated on the formation mechanism of the linguistic and symbolic Second Threshold driven by primordial cosmic science, which enabled humanity to transcend animal-level object reference and launch ontological inquiries into cosmic order, life and mortality, laying the foundation for the birth and continuous development of civilization. As a companion paper to PFUSRC-055, this research explores subsequent evolutionary questions along the same theoretical axis: how civilizations operate after establishing the Second Threshold, what structural limits they face, and where their long-term evolutionary path leads. This paper puts forward that the Second Threshold provides a developmental platform yet possesses finite bearing capacity. When civilizations expand continuously within this fixed cognitive framework, a structural phenomenon termed "the entropy of civilization" emerges. Distinct from physical thermodynamic entropy, civilizational entropy refers to cumulative structural disorder and internal systemic friction generated by growing systemic complexity, information density and competitive intensity within an unchanged cognitive boundary. Primary, secondary, tertiary industries and all emerging sectors essentially function as entropy-absorbing containers built on the Second Threshold, yet their capacity is inherently limited. Once the expansion speed of the threshold framework lags behind the growth rate of civilizational entropy, new industries cease to buffer disorder and instead become new sources of entropy accumulation. Technological iteration can prolong civilization’s operation on the Second Threshold but cannot fundamentally eliminate entropy buildup. The only sustainable long-term path forward is dimensional ascent: crossing the Third Threshold. The Third Threshold does not represent a specific technological stage but a new structural state, in which civilization re-establishes its ontological anchor, allowing historical contradictions to be repositioned within an upgraded frame of reference. The First Threshold (instinct-driven physical survival) bears no involution, as its core pressure originates externally; involution is an inevitable structural outcome of saturated operation on the Second Threshold. After dimensional ascent to the Third Threshold, technological systems degrade into basic infrastructure, while comprehension, creation and exploration of wisdom become humanity’s core civilizational activities. Historical contradictions are not fully resolved but displaced from the central operating logic of civilization. The Third Threshold is not an ultimate terminal, but a new starting point reserved for continuous cognitive exploration and further dimensional breakthroughs.