Originally, the ancient Celtic peoples divided their year into two halves: the light and the dark—from Samhain (pronounced sow-when) to Bealtaine (pronounced byeal-tawneh) and vice versa, respectively. According to local custom, Samhain was the day when the veil between the worlds was lifted and various specters would traverse the land. The ancient sidhe (pronounced sheeve), or the gods and goddesses of Ireland, would receive offerings of cakes, wine, and other gifts in appeasement, ensuring fertility for the land and bringing ill luck upon those who did not respect them. Trick or treat, indeed.

With the coming of the great apostles to the Celtic world—Saints Patrick and Palladius in Ireland, and Saint Columba to the Picts in modern-day Scotland—the absorption of Celtic traditions into the Christian feasts of All Saints and All Souls was both coincidental and Providential. What was once Samhain evolved into Halloween, or All Hallows’ Eve. In the liturgical books before 1955, it was classified as a vigil, similar in manner to Christmas Eve. Together, these observances formed the so-called Triduum of Death, wherein each day serves as a liturgical exemplification of memento mori. Traditionally, the Vespers for the Dead were also said during this period.

Liturgically, Halloween reminds us of the coming holy day through its Introit: Júdicant Sancti gentes et dominantur pópulis: et regnábit Dóminus, Deus illórum, in perpétuum—”The Saints judge nations and rule over peoples, and the Lord their God shall reign forever.” The following day, the Church celebrates all the Saints who have entered into the Beatific Vision, both known and unknown. Originally established as a feast during the Iconoclast Crisis of the ninth century, All Saints’ Day is a universal celebration by which those in Heaven are honored, and the faithful thank the Triune God for His tender mercies toward the just. The prayers of the liturgy reflect this, as the Collect reminds us of our need for their intercession.

Lastly comes the third day: All Souls’ Day. The vestments of the liturgy turn black, and the profound medieval hymn Dies Irae is sung in sequence: “Dies iræ, dies illa, Solvet sæclum in favilla…” The theme is one of judgment and remembrance of death. This feast commemorates all who have passed on, particularly those in Purgatory. Although not a day of fasting, it is fitting that one should partake in the ancient practice of mortification for the sake of the dead—or perhaps visit a cemetery and pray the rosary for the departed, which carries an indulgence.

These three days are colloquially known as the Triduum of Death, through which the Church remembers all saints and all souls—and reminds us that all men are bound to die, while evil itself has been defeated (as symbolized in Halloween). Offer this month of November for all the holy souls in Purgatory and for all the departed—an act of penitence and remembrance.