doctrinal

1. Of, relating to, involving, belonging to or concerning a doctrine.

   […]yet inevitably, [JD] Vance is already giving menacing doctrinal advice to the pope as part of the multi-theatre fallout of Operation Epic Facepalm.

   2026 April 17, Marina Hyde, “Is the pope Catholic? JD Vance thinks he has an answer”, in The Guardian, →ISSN

   1 more example

   Thus it was not only in the doctrinal field that revisionism called into question the traditional belief in the revolutionary mission of the proletariat: the belief was challenged, perhaps more effectively still, by the success of revisionism as a social phenomenon, which robbed socialism of the glamorous prospect of a 'final battle' for universal liberation.

   1978 [1976], Leszek Kołakowski, translated by P[aul] S[teven] Falla, Main Currents of Marxism, volume II: The Golden Age, Oxford: Clarendon Press, translation of Główne nurty marksizmu: rozwój (in Polish), →ISBN, →OCLC, page 114

2. obsoleteDidactic.

   The word of God serveth no otherwise than in the nature of a doctrinal instrument.

   [1594], Richard Hooker, edited by J[ohn] S[penser], Of the Lawes of Ecclesiastical Politie, […], London: […] Iohn Windet, […], →OCLC, (please specify the page)

plural doctrinals

1. A matter of doctrine, or system of doctrines.

   The Doctrinal of Princes

   1531, Thomas Elyot, The Boke Named the Governour […], London: […] Tho[mas] Bertheleti, →OCLC

   1 more example

   His Teaching is not to teach you the Doctrinals of Salvation and of the Son, for he leaves that to Ministers, and to the Bible, to teach you the Doctrinals only in a doctrinal way

   a. 1680, Thomas Goodwin, The Object and Acts of Justifying Faith