Abstract The Unified Dynamic Model of Mind (UDMM) has established the temporal topology of the organism via the Temporal Openness Coefficient Θ(t) = B_future/B_past. Yet the spatial dimension of the organism's existence — how it constructs, navigates, and loses the lived space that makes action possible — has remained formally undeveloped. This paper introduces the Spatial Integration Coefficient Σ(t) as the spatial analogue of Θ(t), defined as the ratio of friction-grounded known space to available but unexplored space. Σ is not a geometric or navigational variable — it is a topological-thermodynamic property of the organism's spatial state-space, derived from the same UDMM Master Equation that grounds all prior constructs. We derive six formal results: (1) the Spatial Gap Field R(x,t) = |I_bio(x,t) − Ω_env(x)| as the spatially-indexed generalization of the vital gap r; (2) Place formation as a spatial attractor in the R-field, governed by accumulated biological friction Γ_spatial(x) = ∫F_ric(x,τ)dτ · (1/ζ); (3) Σ(t) = dim(Ω_known)/[dim(Ω_available) + ε] derived from the spatial diffusion term D∇²φ of the Master Equation; (4) the Axiom of Embodied Space — the body is the irreducible primary spatial attractor, so Σ → 0 requires BAC → 0 (dissociation), not merely external confinement; (5) Spatial entropy S_spatial = −Σᵢ p(x_i)log p(x_i) such that Σ ≈ exp(ΔS_spatial), making Σ an entropic quantity; and (6) the Unified Existence Equation I(t) = G_A · Θ_B · Σ · (1 + λ·Θ_R·Awareness·BAC), establishing that behavioral intent is jointly determined by temporal openness and spatial integration. A friction criterion resolves the digital-space problem: virtual environments expand Ω_known via virtual friction (η_virt << 1) but do not expand the physically-reachable Ω_available. We propose a three-type spatial psychopathology taxonomy and derive four falsifiable predictions, including a novel friction-weighted spatial entropy test using GPS + EDA wearable data.