During this year devoted to St. Paul, there’s been special attention in my diocese to something often overlooked in the modern church: indulgences.

This morning’s New York Times takes another look at them, and what they mean:

The announcement in church bulletins and on Web sites has been greeted with enthusiasm by some and wariness by others. But mainly, it has gone over the heads of a vast generation of Roman Catholics who have no idea what it means: “Bishop Announces Plenary Indulgences.”

In recent months, dioceses around the world have been offering Catholics a spiritual benefit that fell out of favor decades ago — the indulgence, a sort of amnesty from punishment in the afterlife — and reminding them of the church’s clout in mitigating the wages of sin.

The fact that many Catholics under 50 have never sought one, and never heard of indulgences except in high school European history (where Martin Luther denounces the selling of them in 1517 and ignites the Protestant Reformation) simply makes their reintroduction more urgent among church leaders bent on restoring fading traditions of penance in what they see as a self-satisfied world.

“Why are we bringing it back?” asked Bishop Nicholas A. DiMarzio of Brooklyn, who has embraced the move. “Because there is sin in the world.”

Like the Latin Mass and meatless Fridays, the indulgence was one of the traditions decoupled from mainstream Catholic practice in the 1960s by the Second Vatican Council, the gathering of bishops that set a new tone of simplicity and informality for the church. Its revival has been viewed as part of a conservative resurgence that has brought some quiet changes and some highly controversial ones, like Pope Benedict XVI’s recent decision to lift the excommunications of four schismatic bishops who reject the council’s reforms.

The indulgence is among the less-noticed, less-disputed traditions to be restored. But with a thousand-year history and volumes of church law devoted to its intricacies, it is one of the most complicated to explain.

According to church teaching, even after sinners are absolved in the confessional and say their Our Fathers or Hail Marys as penance, they still face punishment after death, in Purgatory before they can enter heaven. In exchange for certain prayers, devotions or pilgrimages in special years, a Catholic can receive an indulgence, which reduces or erases that punishment instantly, with no formal ceremony or sacrament.

There are partial indulgences, which reduce purgatorial time by a certain number of days or years, and plenary indulgences, which eliminate all of it. You can get one for yourself, or for someone else, living or dead. You cannot buy one — the church outlawed the sale of indulgences in 1857 — but charitable contributions, combined with other acts, can help you earn one. There is a limit of one plenary indulgence per sinner per day.

It has no currency in the bad place.

“It’s what?” asked Marta de Alvarado, 34, a bank cashier in Manhattan, when told that indulgences were available this year at several churches in New York City. “I just don’t know anything about it,” she said, leaving St. Patrick’s Cathedral at lunchtime. “I’m going to look into it, though.”

You can look into it at this link. And you can also find a fuller explanation at the Catholic Encyclopedia.