Skeleton, Bones, Skull
A skeleton consists of the remains of humans (or animals) and can symbolize something old that, in its way, still persists.
The Eternal and Resurrection
The "soft tissues" of the deceased disappear over time, but the bones remain. This reflects that something within us endures forever and can resurrect (whether in a sacred or profane manner). This idea is particularly prominent in burial rituals worldwide throughout history and in many religions (not least Christianity). Indigenous peoples’ reverent handling of the bones of hunted animals aimed to allow the prey to return. The same notion recurs in tales and myths. For instance, Thor’s goats could be killed and eaten, and as long as their bones remained intact, they would resurrect the following day.
The Buried
Bones in dreams symbolize something we "buried" long ago, now coming to light. This dynamic pertains to the personal unconscious.
Jung interpreted the skeletons in his famous dream about the house he explored as a symbol of the collective unconscious, inherited parts of ourselves (Mitt liv, pp. 151–152). This reflects the collective unconscious.
The Hidden and the Naked
The skeleton is hidden in living beings. If exposed, the dream may allude to an otherwise concealed "basic structure"—what the figure is fundamentally built from, so to speak, the otherwise hidden framework.
This symbolism also touches on nakedness; that is, the skeleton is stripped bare. It can sometimes symbolize a stripped-down complex, and the horror it evokes may sometimes reflect the pain associated with processing the complex. Furthermore, this is likely one of the reasons shamans were thought to be stripped and reduced to skeletons during initiation.
Death and Transience
Skeletons and skulls are often used as symbols of death and transience. However, this imagery is also employed to describe psychological disintegration in individuals undergoing initiation. Alchemists used skeletons as expressions of the envisioned rebirth of primal matter.
Hamlet’s famous, though not entirely accurately quoted, “To be or not to be,” as he gazes upon a skull, illustrates how contemplating death can lead us to discern life’s true values and the transience of vain pursuits. In short, with memento mori, we gain perspective on existence. Perhaps it is the very awareness of our mortality that enables consciousness—a beast does not know it will die, and could an immortal being be truly self-aware?
Shamanism
Shamans sometimes took on the form of skeletons to symbolize their existence outside of space and time. In a sense, the skeleton represents the archetype of the shaman, as noted by Mircea Eliade (Shamanism, p. 160).
Alchemy
The skull was occasionally used by alchemists as a symbol of the “vessel.” The transformative process takes place, in reality, in the alchemist’s own mind, making the skull a metaphorical crucible for transformation. (See also Head.)