Mythlessness names the condition in which an individual — or an epoch — finds itself without a living, operative myth: no symbolic container adequate to orient psychic life, no narrative tissue connecting ego to the deeper strata of the unconscious. The term acquires its sharpest definition from Jung’s own autobiographical confession, recorded in the Liber Novus materials, that the study of myth revealed to him his mythlessness — an absence he treated as the ‘task of tasks,’ the spur for the self-experimentation that produced analytical psychology itself. Edinger and Peterson extend this diagnostic into cultural pathology: the collective loss of myth is legible in the epidemic spread of addiction, the hollowing of religious symbol-systems, and the proliferation of neurosis among ‘higher types’ who cannot endure the resulting vacuum. Giegerich complicates the remedial impulse, arguing that modernity’s logical structure makes any direct return to myth impossible — that the veil between literal and imaginal has been irreparably rent, and that nostalgic myth-revival is, at best, a game of pretending. Hollis frames mythlessness as the consequence of Kantian critique and scientific empiricism stripping myth of its metaphysical underwriting, while Hillman locates its cultural root in the humanistic reduction of transpersonal powers to merely personal dynamics. Campbell occupies an intermediate position, diagnosing the modern murder of myth through literalism and belief while insisting that mythological function remains indispensable. The term thus sits at the intersection of clinical, cultural, and ontological registers, marking both a diagnosable condition and a horizon of possible renewal.