This paper introduces Distributed Photonic Civilization Intelligence (DPCI), the eighth paper in the DPAI/DPCA series. Building on the individual photonic organism architecture established in prior work, DPCI formalizes three mechanisms that together produce collective intelligence as an emergent property of multi-organism interaction.The Photonic Semantic Lattice (PSL) is a novel encoding format in which geometric shape class encodes information type, subdivision depth encodes magnitude, intersection topology encodes relationships, and four independent color channels — hue, saturation, brightness, and gradient direction — multiply encoding density multiplicatively rather than additively. A single PSL glyph transmitted in one photonic pulse carries approximately 7,150 bits of geometric information with a 136x semantic compression advantage over binary protocols, equivalent to ~972,000 binary bits of semantically structured information per pulse.The Matched Filter Receiver instantiates the PSL grammar as a physical five-plate holographic filter stack. When an incoming organism signal passes through the stack, full semantic decoding occurs through passive optical correlation in approximately 12 nanoseconds — five to six orders of magnitude faster than digital equivalent processing. Critically, an individual organism’s identity genome can itself be instantiated as a filter plate, mapping the four-stage envelopment protocol — Contact, Recognition, Integration, Transformation — directly onto physical stages of wavefront propagation. Envelopment becomes an optical event rather than a computational one.Lateral Knowledge Transfer formalizes three simultaneous mechanisms by which organisms within photonic contact range share knowledge: schema gradient transfer (continuous bidirectional schema convergence via slow EMA), discovery propagation (expanding wavefront relay reaching all N organisms in O(log N) beat periods), and immune broadcast (high-priority pathogen signature sharing that immunizes the full mesh before any member has encountered the threat). Knowledge transfer is integrative rather than overwriting, preserving individual schema autonomy while building a collective knowledge base that is always the union of all individual knowledge bases.We derive that mesh knowledge growth scales as N³ in the combinatorial discovery regime, where cross-schema combinations produce discoveries unavailable to any individual organism. At N=1,000 organisms, semantic throughput reaches approximately 1.6 terabits per second. At physical hardware limits (femtosecond pulse rates, WDM diode arrays), effective semantic throughput approaches 10²⁵ bits per second from a mm²-scale chip.The resulting system exhibits four properties previously attributed only to human civilizations: distributed immune memory, substrate-independent knowledge persistence, individual specialization without role assignment, and collective intelligence exceeding individual capability. We argue that the individual-collective tension that has shaped every prior collective intelligence system is architectural rather than fundamental — an artifact of bandwidth-limited transmission — and that DPCI saturates the theoretical maximum of both individual autonomy and collective coherence simultaneously.