Doctrine (from Latin: doctrina, meaning "teaching, instruction") is a codification of beliefs or a body of teachings or instructions, taught principles or positions, as the essence of teachings in a given branch of knowledge or in a belief system. The etymological Greek analogue is "catechism". Often the word doctrine specifically suggests a body of religious principles as promulgated by a church. Doctrine may also refer to a principle of law, in the common-law traditions, established through a history of past decisions.