Mormons have a scriptural canon consisting of the Bible (both Old and New Testaments), the Book of Mormon, and a collection of revelations and writings by Joseph Smith known as the Doctrine and Covenants and Pearl of Great Price. Mormons, however, have a relatively open definition of scripture. As a general rule, anything spoken or written by a prophet, while under inspiration, is considered to be the word of God. Thus, the Bible, written by prophets and apostles, is the word of God, so far as it is translated correctly. The Book of Mormon is also believed to have been written by ancient prophets, and is viewed as a companion to the Bible. By this definition, the teachings of Smith's successors are also accepted as scripture, though they are always measured against, and draw heavily from the scriptural canon.