"During my September 3 dialogue with Timothy George at Wheaton College, we briefly discussed St. Thomas Aquinas' denial of the doctrine of the Immaculate Conception of the Virgin Mary, which later became a dogma of the Catholic Church. One of the points I made was that St. Thomas' understanding of Mary's holiness was far from the Protestant view. In fact, for St. Thomas, Mary, though not conceived without original sin, it was removed by God after she was conceived (technically, after she was "animated"). She was also was the recipient of an abundance of grace so that she may be protected from all actual sin. So, St. Thomas' view, though not the view currently held by the Church as dogma, contained within it some of the same logic on which the Church's dogma is based." [source]
Well, if you rub the edges of a square down for a while, you can eventually fit it in the round hole.