Detail from “The Immaculate Conception” (1767-69) by by Giovanni Battista Tiepolo, in the Museo del Prado, Spain. (Wikipedia)
Last December, I wrote an article for Catholic World Report on the Immaculate Conception: “Why I came to believe that Mary was conceived without sin.” I argued that it was (1) a matter of typology, that Mary had to be sinless so that she could be in Eve’s original state to undo through her obedience what Eve did through her disobedience, and showed how the stories of Zechariah, Elizabeth, and Mary suggested Mary’s sinlessness. I also pointed out (2) how Marian teachings are a reflex of Christology; we Catholics believe what we do about Mary because of what we believe about Jesus.
I received some correspondence from faithful, thoughtful Catholics concerned that I had described the Immaculate Conception as “necessary” and not merely fitting. Claiming the Immaculate Conception is necessary (so my interlocutors assert) involves a necessary infinite regress, that St. Anne and her mother and her mother before her would need to be sinless for Mary to be sinless, and, further, that by using the word “necessary” I had given Protestants ammunition to deride the doctrine as absurd (thanks to the infinite regress needing to make even Eve sinless at the time of the delivery of her children, which of course is not the biblical case) and also ammunition for them to deride the doctrine as a raw exercise of authoritarian power.