Paper I of the Pattern Field Theory series. This document establishes the core ontology of coherent identity, defining pattern, basin, observer, and interaction within model space. It introduces identity as persistence across depth and provides the conceptual basis for the Allen Orbital Lattice framework.First published and timestamped December 18, 2025 on Academia.edu and Patternfieldtheory.com/papers. Timestamp and documents available at PatternFieldTheory.com.Republished after slight update at Academia.edu and timestamped January 6 2026. Subsequent papers develop:– Allen Orbital Lattice specification– Coherons and Phase Alignment Lock– Interaction and interference mechanics All works are independently timestamped via opentimestamps.org and Internet Archive and are also available at patternfieldtheory.com/papers.