Doctrine (Latin: doctrina) is a codification of beliefs or "a body of teachings" or "instructions", taught principles or positions, as the body of teachings in a branch of knowledge or belief system. The Greek analogy is the etymology of catechism.

Often doctrine specifically connotes a corpus of religious dogma as it is promulgated by a church, but not necessarily: doctrine is also used to refer to a principle of law, in the common law traditions, established through a history of past decisions, such as the doctrine of self-defense, or the principle of fair use, or the more narrowly applicable first-sale doctrine. In some organizations, doctrine is simply defined as 'that which is taught', in other words the basis for institutional teaching of its personnel internal ways of doing business. — From Wikipedia, the free encyclopedia