doctrine
This word carries a heavy weight of authority and rigidity. It suggests a codified system of truth that is not meant to be questioned, but rather followed and disseminated. While a theory is a proposal to be tested, a doctrine is presented as an established law or an absolute truth. In political or military contexts, it refers to a strategic framework that guides decision-making, such as the Monroe Doctrine. It often implies a level of institutionalization where the beliefs are woven into the very structure of an organization, making them difficult to change without a complete systemic overhaul.
Countable when referring to a specific set of beliefs belonging to a group (the various doctrines of the church). Uncountable when referring to the general concept of teaching and dogma (the spread of doctrine).