Paper I of the Principia Moralia Theophysics Doctoral Series (DT-003). This paper formalizes the Pharisee Decay Function — a 9-step cycle describing how knowledge systems built to serve truth progressively displace it. The pattern is shown to be structurally inevitable rather than contingent on individual failure, operating identically across religious, academic, medical, legal, and technological institutions. The decay is formalized through the Knowledge-Wisdom Transform: W = T^a K^(1-a) H(F - Fc) * F(S,t). When a > 1, knowledge accumulation without truth-alignment produces diminishing and eventually negative returns on wisdom. The Heaviside gate function H(F - Fc) encodes Proverbs 9:10 as a binary phase transition: epistemic humility is a gate condition, not a gradient. Empirical grounding is provided through three peer-reviewed cognitive mechanisms: the Bias Blind Spot (Pronin et al., 2002), Naive Realism (Ross & Ward, 1995), and the Introspection Illusion (Pronin, 2007). Cross-domain mapping is applied across 45 institutional domains. The paper includes full bias declaration (Biaxiosum), four explicit kill conditions, and self-identifies its own framework as structurally vulnerable to the same decay. Derived with Claude Opus 4.6. Author: independent researcher, self-funded, Christian theist, no institutional affiliation.