On this day in 1904 Pope St. Pius X issued an encyclical on the Immaculate Conception. The issuance was in honor of the fiftieth anniversary of the promulgation of the dogma by Bl. Pius IX on December 8, 1854. The new encyclical was called Ad Diem Illum Laetissimum.
A century ago, most Catholics were less educated than they are today. Indeed, a good proportion of them were illiterate, and most of the rest, even in a country such as the U.S., could not hope to go beyond high school. Yet it seems that the Catholics of those days had less confusion about the dogma of the Immaculate Conception than do the Catholics of today.
The Immaculate Conception is like the Virgin Birth: Most people are mixed up about it. Most non-Catholics, and not a few Catholics, think the Virgin Birth has something to do with the birth of the Virgin, when in fact it is the belief that our Lord was born of a virgin.
Similarly, many people misunderstand the Immaculate Conception. They think it has to do with the conception of Jesus. It doesn't. It concerns the conception of Mary in her mother's womb. It is the teaching that Mary was conceived exempt from the stain of original sin—unlike all the rest of us, no matter how highly we might think of ourselves!
In 1904 Pius X issued a straightforward and, shall we say, pious encyclical about this dogma. If a pope of our time were to do the same, he would have to engage in a more extensive basic catechesis, not just for the sake of non-Catholics who might read his words but for most Catholics, too.
Such is progress.