During his homily at St. Peter’s Basilica for the World Day of Peace and the Solemnity of Mary, Mother of God — New Year’s Day — Pope Benedict XVI offered the world a most thought-provoking reflection on peace. The Holy Father developed the point that peace begins when we look upon the face of another person.

This looking upon the face of another, as Benedict was careful to explain, will find the “depth” of the human face “only if we have God in our hearts.” If we do, then “we are in a condition to detect in the face of others a brother in humanity — not a means, but an end, not a rival or an enemy, but another ‘I,’ a facet of the infinite mystery of the human being.”

The looker who has an empty heart perceives nothing more in other faces than flat images. But the more we are inhabited by God, the Pope pointed out, the more sensitive we are to his presence in others. Hence the significance of a common Father who loves us all despite our weaknesses and limitations. In looking into the face of another, one can experience the unveiling of the face of God.

The face speaks. It speaks of love and is the beginning of all subsequent discourse. The mother’s face is like the face of God for her baby. Looking into her face, the infant comes to believe that the world outside the womb is safe and trustworthy. The child picks up these messages intuitively and immediately as he studies the face of his loving mother.

In a world of widespread depersonalization, in which people move about side by side rather than face to face, a reflection on the profound significance of the human face is critically needed. In pornography, for example, as psychiatrist Leslie Farber and others have pointed out, the fig leaf is transferred to cover the face. In this transference, the impersonal gains ascendancy over the personal. It also signifies a suppression of the spiritual.

The great Russian Orthodox philosopher Nikolai Berdyaev, like Benedict, understood how the spiritual order can manifest itself in the human face. In Slavery and Freedom, he writes: “The face of man is the summit of the cosmic process, the greatest of its offspring, but it cannot be the offspring of cosmic forces only; it presupposes the action of a spiritual force, which raises it above the sphere of the forces of nature. The face of man is the most amazing thing in the life of the world; another world shines through it. It is the entrance of personality into the world process, with its uniqueness, its singleness, its unrepeatability.”

Darwinian evolution cannot begin to explain the emergence in the cosmos of the face as a bearer of the spiritual. For Darwin and his disciples, the spiritual realm exists wholly outside of their limited sphere of discussion concerning physical variations and chance mutations. As the noted geneticist Theodosius Dobzhansky has pointed out, human beings properly belong to an “ethical” not a “gladiatorial” mode of existence. The “ethical” is not something that evolves from matter.

Max Picard, a Swiss psychiatrist whose book The Human Face has earned him renown as “the poet of the human face,” states that God enters man’s face as a friend enters the house of a friend — without a stir. The face, for Picard, is a tempered image; it is the mildness of God that appears in the face of man.

In Crossing the Threshold of Hope, Pope John Paul II strongly disagrees with the common accusation that defenders of the unborn are “obsessive.” In making his case he draws on the ethical significance of the human face as a kind of existential and intensely personalized correlation to the Sixth Commandment. At this point, he introduces Emmanuel Lévinas’ philosophy of the face, one that has roots in the Old Testament Psalms and in the writing of the prophets.

Lévinas, who, like his Jewish comrades, experienced the tragedy of the Holocaust, ingeniously links together the human face and the commandment “Do not kill.” He thereby provides, in John Paul’s estimation, “a testimony for our age, in which governments, even democratically elected governments, sanction executions with such ease.” Bureaucracies are not always sensitive to the moral meaning that is inscribed in the human face.

Lévinas develops his “philosophy of the face” in a most remarkable book: Totality and Infinity (1961). He states that the first word of the face is “Thou shalt not kill.” It is an order, a commandment that is registered in the very appearance of the face, one that is more compelling than words, more decisive than any dogma.

According to Lévinas, in the access to the face, there is also an access to the idea of God: “To my mind,” he writes, “the Infinite comes in the signifyingness of the face. The face signifies the Infinite. … When in the presence of the Other, I say, ‘Here I am!’; this ‘Here I am!’ is the place through which the Infinite enters into language. … The subject who says ‘Here I am!’ testifies to the Infinite.”

For Lévinas, the face-to-face encounter with the other discloses the other’s weakness and mortality. The face is, as it were, naked, destitute, without defense. Its command is: “Do not leave me in my solitude.” In looking at another’s face, one senses the supreme inappropriateness of violence and, at the same time, the profound obligation to love. The command to treat the other with justice is registered in the human face. But it takes a godly person to read it properly.

Returning to Benedict’s XVI’s homily: The Holy Father acknowledges that the human face can also be marked by the harshness of life and by the effect of evil. But “the faces of innocent little ones are a silent call to us to take responsibility: Before their helplessness, all of the false justifications for war and violence come crashing down.” The face carries a plea to defend and protect.

Pope Benedict then draws a connection between respect for the person and protection of the environment: “If the person is degraded, the environment is degraded; if culture tends to nihilism — if not in theory, then in practice — nature cannot fail to pay the consequences.”

There is a reciprocal relationship between the face of the person and the face of the environment. The distorted visages of emaciated children are directly connected to an environment that has not served them justly or properly.

The call to justice is written on the face of the human person, though it takes a godly person to see this. Those who argue that religion has been history’s leading cause of violence and warfare fail to recognize this primordial fact. The Judeo-Christian tradition clearly, repeatedly and consistently reminds its disciples that a refutation of war is written on the human face. Peace begins when one sees the inscription in the face of the other not to kill and, by honoring that inscription, renders him justice.

Pope Benedict, by connecting the human face with the “face” of the environment, is offering an integrated vision — one in which philosophy, theology, ethics and care for the environment all blend together in a consistent and meaningful pattern. His New Year’s Day 2010 homily has profound, realistic and rich implications for the whole world at a most critical time.

Donald DeMarco is professor emeritus at St. Jerome’s University

and an adjunct professor at Holy Apostles College & Seminary and Mater Ecclesiae College.