Resonance occupies a richly polysemous position in the depth-psychology corpus, operating simultaneously as a neurobiological mechanism, an archetypal process, a philosophical principle of individuation, and a phenomenological quality of dream imagery. Daniel Siegel anchors the term most precisely in neuroscience, identifying ‘resonance circuits’—orbitofrontal, anterior cingulate, and midline prefrontal structures including mirror neurons—as the neural substrate through which one mind attunes to and internally simulates another’s state. This interpersonal-neurobiological usage frames resonance as the physiological bedrock of empathy, attachment repair, and therapeutic change. Michael Conforti extends the concept into Jungian field theory, treating resonance as the mechanism by which clinical repetitions entrain both patient and therapist to underlying archetypal constellations. Mario Jacoby pursues a cognate idea through the mythological register, arguing that the Muses were created precisely to give resonance to existence—establishing mirroring and affirmation as ontological necessities for healthy narcissism. Richard Schwartz grounds resonance in a quasi-physical field ontology borrowed from wave mechanics, where Self-to-Self vibration across persons constitutes transpersonal connection. Erik Goodwyn formalizes ‘psychological resonance’ as a measurable property of dream images. Gilbert Simondon, operating from a philosophy-of-individuation standpoint, treats internal resonance as the living being’s constitutive self-relation, the very process by which organisms continuously re-individuate rather than merely equilibrate. These positions are in productive tension: the neuroscientific, the archetypal, the ontological, and the phenomenological.