You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Immaculate_Conception

Context:
Popular opinion remained firmly behind the celebration of Mary's conception. In 1439, the Council of Basel, which is not reckoned an ecumenical council, stated that belief in the immaculate conception of Mary is in accord with the Catholic faith. By the end of the 15th century the belief was widely professed and taught in many theological faculties, but such was the influence of the Dominicans, and the weight of the arguments of Thomas Aquinas (who had been canonised in 1323 and declared "Doctor Angelicus" of the Church in 1567) that the Council of Trent (1545–63)—which might have been expected to affirm the doctrine—instead declined to take a position.

Question:
How did the Holy Roman Church rule on the matter of the festivals ?

stated that belief in the immaculate conception of Mary is in accord with the Catholic faith.