Doctrina and “doctrine” may certainly be considered cognates when they denote general tenets or principles such as, for example, la doctrina del fruto del árbol envenenado (the fruit-of-the-poisonous tree doctrine) or the doctrina del levantamiento del velo societario (the veil doctrine [or] the piercing of the corporate veil doctrine).
But when referring to the authoritative writing of jurists, legal scholars and law professors, “doctrine” is not an appropriate translation for doctrina. As used in Spanish legal contexts, doctrina most often denotes the writings of law professors and legal commentators, and may be appropriately translated as “legal scholarship,” “academic opinion,” “legal (or) academic writing,” or “the opinion of legal scholars,” etc. Thus, in this context an expression such as autorizada doctrina is “authoritative academic opinion,” and a principle that is aceptado en doctrina is “accepted by legal scholars.”
In other respects, in the context of court decisions doctrina is often an ellipsis for the expression doctrina jurisprudencial and denotes “caselaw.” Thus, as used in the opinions of the Spanish Constitutional Court (Tribunal Constitucional) or Supreme Court (Tribunal Supremo), expressions such as nuestra reiterada doctrina or nuestra doctrina pacífica refer to the courts’ “established (or) settled caselaw,” while recurso de casación para la unificación de doctrina denotes a “Supreme Court appeal to unify conflicting caselaw.” And, in more general contexts, the expression legislación, jurisprudencia y doctrina refers to “laws, caselaw and legal scholarship (or) academic opinion.”