Bodies of man
The four lower bodies are four sheaths consisting of four distinct frequencies that surround the soul—the physical, emotional, mental, and etheric—providing vehicles for the soul in her journey through time and space. The etheric sheath, highest in vibration, is the gateway to the three higher bodies, which are the Christ Self, the I AM Presence, and the causal body.
See also
Sources
Mark L. Prophet and Elizabeth Clare Prophet, Saint Germain On Alchemy: Formulas for Self-Transformation.