A rule or principle of the law established through the repeated application of legal precedents.
Common law lawyers use this term to refer to an established method of resolving similar fact or legal issues as in "the doctrine of stare decisis".
Jurists with a civil law leaning use this refer to the least authoritative of the three main sources of legal research. After (1) statutes or legislation, and (2) judgments, there are writings or written opinions by learned authors, such as articles in law journals, hard-copy of electronic, or law books (such as The Law of Contracts by S. M. Waddams, Canada Law Book Inc., Toronto, 1999).
In some areas, even the common law defers extensively to doctrine. For example, Allen in Law In The Making points out that in the areas of real estate and conflict of laws, the common law courts often defer to the work of text writers.
And both the works of Bracton and Blackstone, in their time, and doctrinal writings, carried considerable weight in the courts of common law.
That the civil law defers to doctrine stems from Roman law, it's precursor, where the writings of jurists such as Gaius and Ulpianus carried tremendous weight in the court (see, for example, the Law of Citations of 426 AD).
Common law calls this juristic writing or even legal literature!
REFERENCES:
- Allen, C. K., Law In The Making, 6th Ed. (Oxford: Clarendon Press, 1927).
- Buckland, W. and McNair, A., Roman Law and Common Law (Cambridge: University Press, 1965), pages 10-11.