Oesterley describes the beliefs that pre-Christian Hebrews and Semites held regarding the afterlife and the immortal nature of humans. The nature, form and evolution of these beliefs are derived from the Tanakh (Old Testament), comparisons with the beliefs and mythologies of neighboring cultures, and archeological finds. To develop a full study, additional beliefs of these people are also considered, including the beliefs of the constituent parts of humans; demonology, angelology, shades and the Satan; the home of the dead, ancestor worship, necromancy, and burial customs. Oesterley also hypothesizes on how primitive beliefs in immortality may have developed in pre-Christian times.