All early peoples sacrificed human beings. One has only to remember Agamemnon's sacrifice to angry Artemis of the most beautiful thing he possessed, his daughter Iphigenia. But this was a story of the Greek Iron Age, no more present to the Romanized world into which Patrick was born than public executions are to ours. For us, it is a strain to find any surviving elements of sacrifice—cut flowers, Christmas trees, vigil lights, and the Mass may be the last vestiges—but in the Roman world animal sacrifices were still offered.

It seems that at some point in the development of every culture, human sacrifice becomes unthinkable, and animals are from then on substituted for human victims. The story of the binding of Isaac in Genesis may constitute symbolically just such a turning point in the history of the Jews—when Abraham's God tells him it is no longer required that he sacrifice his only son but may substitute a ram instead. The Irish had not reached this point and were still sacrificing human beings to their gods when Patrick began his mission.

They sacrificed prisoners of war to the war gods and newborns to the harvest gods. Believing that the human head was the seat of the soul, they displayed proudly the heads of their enemies in their temples and on their palisades; they even hung them from their belts as ornaments, used them as footballs in victory celebrations, and were fond of employing skull tops as ceremonial drinking bowls. They also sculpted heads—both shrunken, decapitated heads and overbearing, impassive godheads—and a favorite motif was the head of a tri-faced god, for three was their magical number, and gods and goddesses often manifested themselves as three.

The Irish would have said here [in Christ] is a story that answers our deepest needs.

Why do human beings do these things? The psychological mechanism is not far to find, since there is probably not a reader—even the most convinced atheist—who has not offered from time to time an old-fashioned quid pro quo prayer: if you let me pass this exam, I will return to church; if you make sure my wife doesn't learn of my infidelity, I will give my next bonus to charity. The theology—the view of god—that lies behind these imprecations is of an arbitrary trickster, a bad parent who can be coaxed, flattered, and manipulated. If belief in such a god is strong and primitive enough, it is easy to see how it can lead to human sacrifice: Here, take him, not me! The impassive godhead demands someone's blood. Let it not be mine! And if we study the faces of the Celtic gods, we can have no doubt that only blood could satisfy most of them.

But we delude ourselves about the complex history of religious feeling if we think that all sacrifice—human included—can be reduced to this base motive. Whatever the Irish felt, we feel. For all the terror of the Celtic cosmos and the blood thirstiness of the Celtic gods, no human society could hold together for long if it understood sacrifice only along the lines of the savage tribe in King Kong, offering terrified beauties to the Beast.

This caricature is belied by the most direct evidence of human sacrifice that we have found to date—the prehistoric corpses of Tolland Man, Grauballe Man, the Borremose Man, dug out of Danish bogs in the 1950s, and an even more intriguing discovery recently made in a remote English bog. The Danish bodies may be Celtic; the English one—a man discovered in 1984 and dug out of the peat of Lindow Moss, an ancient bog south of Manchester—certainly is, and may even be Irish.

These bodies all owe their amazing state of preservation to the chemical properties of the peat, which has leatherized the skin but left it otherwise intact, so that we can see every physical detail—even smiles lines around the eyes—just as we could have in life. All the bodies were sacrificed, and all the faces are at peace. In other words, all went willingly, one might almost say happily, to their sacrificial deaths—like Isaac, trusting to the last in the goodness of the sacrificing priest and, even more important, in the goodness of the father god.

That Lindow Man was a sacrifice there can be little doubt. His hands are uncalloused, his nails beautifully manicured. Thus, he was an aristocrat, though, strangely, he cannot have been a warrior, for his body shows no evidence of the scars of battle. Indeed, leaving aside for the moment the marks of his elaborate execution, he appears to be without blemish of any kind. According to British archaeologists Anne Ross and Don Robins, he was a druid prince who had come from Ireland about A.D. 60, as the Romans were asserting their control and expunging druidism. He offered himself as a sacrifice to the gods for the defeat of the Romans. Ross and Robins even think they know his name—Lovernius, the Fox-Man. Certainly, he had dark red hair and a full beard (like a druid, unlike a bushily mustached warrior) and wore around his left forearm a circlet of fox fur, the naked man's only adornment.

The most conclusive evidence that the bog men were sacrificed is the story their bodies tell of the manner of their deaths.

Each submitted himself naked to an elaborate, ritualized Triple Death. In the case of Lindow Man, for instance, his skull was flattened by three blows of an ax, his throat garroted by a thrice-knotted sinew cord, his blood emptied quickly through the precise slitting of his jugular. Here is the ancient victim of sacrifice, the offering made out of deep human need. Unblemished, raised to die, possibly firstborn, set aside, gift to the god, food of the god, balm for the people, purification, reparation for all—for sins known and unknown, intended and inadvertent. Behold god's lamb, behold him who takes away the sins of all.

Patrick declared that such sacrifices were no longer needed. Christ had died once for all. I'd bet he quoted Paul, his model, who in his letter to the church at Philippi recited this mysterious poem about sacrifice, the oldest Christian hymn of which we have record:

Though he possessed divine estate
He was not jealous to retain
Equality with God.

He cast off his inheritance,
He took the nature of a slave
And walked as Man among men.

He emptied himself to the last
And was obedient to death—
To death upon a cross.

And, therefore, God has raised
him up
And God has given him the Name-

That at the name of Jesus all
In heaven high shall bow the knee
And all the earth and depths

And every tongue of men proclaim
That Jesus Christ is Lord—
To the glory of the Father.

Yes, the Irish would have said, here is a story that answers our deepest needs—and answers them in a way so good that we could never even have dared dream of it. We can put away our knives and abandon our altars. These are no longer required. The God of the Three Faces has given us his own Son, and we are washed clean in the blood of this lamb. God does not hate us; he loves us. Greater love than this no man has than that he should lay down his life for his friends. That is what God's Word, made flesh, did for us. From now on, we are all sacrifices—but without the shedding of blood. It is our lives, not our deaths, that this God wants. But we are to be sacrifices, for Paul adds to the hymn this advice to all: "Let this [same] mind be in you, which was also in Christ Jesus."

From How the Irish Saved Civilization by Thomas Cahill, copyright © 1995 by Thomas Cahill. Used by permission of Doubleday, a division of Random House, Inc. For online information about Random House, Inc. books and authors, see: