Jacques Vallée’s career charts a unique trajectory from scientific inquiry to a speculative framework that engages with esoteric traditions. Initially, Vallée approached UFOs with a data-driven, empirical methodology. However, his focus later shifted to comparative folklore, finding parallels between historical narratives of fairy encounters and modern UFO reports. This evolution culminated in his “control system” theory, which posits an unidentified intelligence that regulates human perception and access to the phenomenon.

This research will trace Vallée’s intellectual development across these phases, examining how his synthesis of scientific methodology, comparative mythology, and speculative metaphysics aligns with elements of modern esotericism. It will explore the epistemological tensions in his work and consider his relevance to contemporary UAP studies, which increasingly accommodate interdisciplinary, non-positivist approaches. By examining Vallée as a dual scientist and esoteric thinker, we offer a critical perspective on the broader negotiation between rationalism and visionary speculation in the study of anomalous phenomena.