Secular Institute of the Schoenstatt, Sisters of Mary
Post-Doctoral Fellow, Institute for Church Life, University of Notre Dame
Christmas is a feast for families, beginning with the Holy Family. But is it also a feast of the Family of the Holy Trinity? The “Trigonometry” featured in this year’s display of Christmas crèches at the University of Notre Dame answers “yes” to this question.
Trigonometry (from Greek trigōnon, “triangle” and metron, “measure”) is a branch of mathematics investigating the relationships of lengths and angles in triangles. For many of us this science can be compared to the proverbial book with seven seals with which we have become acquainted while in High School. We may still remember that the sides of a right-angle triangle and the angles between those sides have fixed relationships. Provided we know at least the length of one side and the value of one angle, we can determine all other angles and lengths. Trigonometry and its functions are implemented for example in satellite navigation systems.
Christian iconography, too, avails itself of this science when portraying the Mystery of the Triune God in the form of a triangle. This depiction, as limited and fragmentary as it may be, can tell us something about the “Divine Trigonometry.” The triangle’s equilateral sides symbolize the coequal nature of the three divine persons (est), while the maximal separation of the vertices highlights their distinction (non est). Hence, the rapport within the communion of the Triune God is absolute communion and simultaneous free unfolding of the differences of the Persons and their attributes. Moreover, the Trinity’s modus of interaction in pursuit of the common plan and goal (creation, redemption, sanctification) enables us to better, though never completely, comprehend the Revelation about the Triune God! The Council of Florence explained this Trinitarian mode of being as follows:
Through this unity…the Father is completely in the Son and completely in the Holy Spirit;
the Son is completely in the Father and completely in the Holy Spirit;
he Holy Spirit is completely in the Father and completely in the Son (DS 1331).
Hence, the three distinct divine Persons are the same Being, the same Life, the same God, and are united in a communion of Love. The reciprocal rapport unique to the Divine Trigonometry is described by the Greek Fathers as perichoresis (round dance) and by the Western Fathers as circumincessio (mutual indwelling). Taking our bearings from this tradition, we observe complete openness and receptiveness among the Persons of the Trinity to each other. In their Being each contains the others and is contained by them. Revelation permits us to define each of the three Persons exclusively on the basis of how they relate to the other two. In the words of St. John Paul II, “the Father is pure Paternity, the Son is pure Sonship, and the Holy Spirit is pure Nexus of Love of the two, so that the personal distinctions do not divide the same and unique divine nature of the three.”
The reverse of the current $1 bill shows an unfinished pyramid topped by the Eye of Providence within a triangle. This portrayal of God’s Eye discloses another dimension of the Divine Trigonometry. Dating back to the Middle-Ages, the triangle with a pointed top indicates the unique position of God Father within the Trinity. St. Irenaeus speaks of the Father’s ‘two hands,’ the Son and the Spirit. The Father may be seen as the ultimate authority in his fatherly compassionate love which is the principle cause of God’s activity. The Father is the sender of the Son and the Holy Spirit, but does not himself go. Thus, the Divine Trigonometry has its origin in the Trinity’s eternal plan and extends from the ineffable communion of the Father, Son and Holy Spirit.
The classic example of this divine economy is the Incarnation celebrated on March 25 and made visible nine months later on Christmas. Its dynamics is revealed through the Scriptures as a bonum diffusivum sui (good diffusive of itself). It is a love that does not remain closed in a perfect circle of light and glory but offered as a creative, self-gift. God’s Love proceeds from the Father to the Son who by his “departure” transmits to the Holy Spirit the new salvific self-giving of God. The Triune God, however, did not want to accomplish this plan without the cooperation of humanity.
Luke’s account of the Annunciation recounts the Trinity in dialogue with Mary of Nazareth. As a result of Mary’s free and loving cooperation with God’s plan the total gift of herself in undivided love is rewarded with God’s gift to her, manifest in her divine maternity, and culminating in their mutual Gift – Jesus Christ!
The Divine Trilogy provided that the eternal Son of God be born and sheltered in the love of a human family which hence becomes a mirror of God’s communion. Pope emeritus Benedict XVI expressed it this way, “The human family is, in a certain sense, the icon of the Trinity because of the love between its members and the fruitfulness of that love.” In other words, the divine trigonometry seeks a continuation and reflection on earth.
Among the 30 crèches exhibited presently on the campus of the University of Notre Dame, one conveys this holy trigonometry. The Swiss nativity set designed by Elizabeth Kuchen can be admired at the Morris Inn. Its foundation is a triangle-symbol of the Trinity- surrounded by daisies arranged in groups of three. Joseph, Mary and the manger with Baby Jesus form a triangle; the same holds true for the magi kings surrounding them. The A-framed shelter, complemented by its firm foundation is triangular and even the smoke—or is it a lightning rod?—on top of the roof resembles an open triangle. The idyllic scene radiating simplicity and harmony allows the onlooker to be drawn to the fruit of an existence founded in God’s Trigonometry. At the points of each triangle stands a person-free and autonomous-yet centered on the other, particularly on the Child in the manger. Each one has a unique role and mission and therefore can complement the others. Above all, each figure is supported by the base—symbol for the triune communion—on which they are standing. For that reason, this holy trigonometry mirrors the Divine Trigonometry!
But there is still more! Did you notice the four figures (only two are visible in the above photo) standing in the background? Who are they? The answer is up to our imagination. Allow me to share my thoughts. The number four alludes to a finite, transitional state which is perhaps the reason why they are placed on a lower level. Could they be the representatives of those who approach and observe this Divine Mystery skeptically, yet longingly? The four figures are in need of a lift in order to become part of the harmony and peace of the Holy Trigonometry, lest they turn around and get lost in the darkness! Authentic holy trigonometry—a communion in which each is completely open to the other—moves towards the disenfranchised. The Divine Child at the center of the crèche is the measuring stick for each one of us. From His Incarnation to His death He consumed himself by inviting all into the communion of the Divine Trigonometry. As his brothers and sisters we are invited to do likewise. The Father needs us to be His arms in the world today. Are you ready to be sent and to bring the Gift of the Father to our world in darkness? Then peace and joy will triumph and the Miracle of Love is celebrated in heaven and on earth!
 The Trinity’s Embrace – God’s Saving Plan. A Catechesis on Salvation History (Boston 2002), 183.
 Angelus, December 27, 2009.