underworld is psyche. When we use the word underworld, we are referring to a wholly psychic perspective, where one's entire mode of being has been de-substantialized, killed of natural life, and yet is in every shape and sense and size the exact replica of natural life. The under-world Ba of Egypt and the underworld psyche of Homeric Greece was the whole person as in life but devoid of life. This means that the underworld perspective radically alters our experience of life. It no longer matters on its own terms but only in terms of the psyche. To know the psyche at its basic depths, for a true depth psychology, one must go to the underworld.
— James Hillman
Hillman is not describing a place you visit and return from. The underworld is not a therapeutic detour — not the difficult phase before you resurface, renewed, to the life you recognize. That reading would betray the passage. De-substantialization is not a temporary condition; it is a mode of perception. When the underworld takes you, the world you knew continues in exact replica — same faces, same rooms, same hungers — but none of it weighs what it used to. This is not depression to be corrected. It is the psyche disclosing its own nature.
What this strips is the assumption that life matters on its own terms, that vitality is self-recommending, that the full-blooded and upward-moving carries its own warrant. The underworld reverses the priority: life becomes legible only from below, only when held against its own shadow. Depth psychology earns its name here — not by descending to retrieve something and bring it back into the light, but by recognizing that the underworld perspective is itself the knowing. The Ba, the Homeric shade, is not a diminished person; it is the whole person seen from the angle that sees truly. The direction is not back up.
James Hillman·The Dream and the Underworld·1979