THE'URGY, noun [Gr. God, and work.] The art of doing things which it is the peculiar province of God to do; or the power or act of performing supernatural things by invoking the names of God or of subordinate agents; magic. This has been divided by some writers into three parts; theurgy or the operation by divine or celestial means; natural magic, performed by the powers of nature; and necromancy, which proceeds by invoking demons.