Pneumatology (from πνεῦμα, spirit, and λόγος, word) is the doctrine of spiritual existence. Considered as the science of mind or spirit, pneumatology consists of three parts: treating of the divine mind, theology; the angelic mind, angelology; and the human mind. This last is now called psychology, "a term to which no competent objection can be made, and which affords us, what the various clumsy periphrases in use do not, a convenient adjective, psychological" (Sir W. Hamilton, Reid's Works, p. 219, note). The belief in a return from the dead, apparitions, and spirits is largely incorporated in the traditions of the Jews, and prevailed almost universally in the scholastic ages. The mystic Jacob Bohme and Emanuel Swedenborg made it a popular phase of belief in Northern Europe, and Martinez Pasqualis and his disciple St. Martin caused it to prevail among the people of France and in Southern Europe. All these teachers have given accounts of the orders of spiritual beings who held communication with the living. In our own day spiritualism has branched out so extensively that it will be treated separately under that heading.