The cell is the smallest unit of life. Some living things, like bacteria and many protists, are composed of only one cell each. Most other living things are composed of many cells. But every single living thing begins life as a single cell.
Cells were first discovered when microscopes were invented in the early 1600s. They were named by the English scientist Robert Hooke in 1665, who observed dead cork cells through one of the first microscopes. The empty plant cell walls reminded him of the monks’ cells in a monastery, hence the term “cell.”1 As microscopes have improved over the centuries, so has our understanding of cells. We now know that each cell is marvelously complex, even in the “simplest” organism: “Rather than the simple compartments observed by Hooke, cells are much more like schools, cities, or even countries in their organization. There are multiple compartments with specialized roles that work together to carry out all the life functions of the cell.”2 All biological life is ultimately dependent on the interplay of the parts of the cell.
Surrounding the cell and maintaining its integrity is the cell membrane, which “controls what enters and exits the cell.”3 The cell membrane is critical to the very identity of the cell:
The defining feature of a cell is a membrane—a chemical structure that divides the outside world from the interior of the cell. With the protection of a membrane, a cell can maintain different conditions inside than prevails outside. For example, cells can concentrate nutrients in their interior so that they are available for energy production, and can prevent newly made structural materials from being washed away. In the absence of a membrane, the large array of metabolic reactions necessary to sustain life would quickly dissipate.4
Without a cell membrane, there can be no cell.
Through the process of “active transport,” the Church expends the energy of discernment in her work of “inculturation” of the life of the cell of the Church.
The Catholic Church is like a cell in its marvelous complexity and internal harmony. As a cell is necessary for our biological life, so the Catholic Church is necessary for our spiritual life. For the cell of the Church to live and give life, it must maintain its cell membrane. The “cell membrane” of the Catholic Church is its teachings, its clergy, and its laws. As the Baltimore Catechism explains, “The Church is the congregation of all baptized persons united in the same true faith, the same sacrifice, and the same sacraments, under the authority of the Sovereign Pontiff and the bishops in communion with him.”5 Without these unifying realities, the Catholic Church would not be herself.
Maintaining a cell membrane is critical to maintaining the life of cell, yet that membrane is not rigid and impermeable. It defines the cell, but it also lets certain things come in and other things go out: “the major property of the plasma membrane [cell membrane] is its semi-permeability—the membrane allows passage of specific molecules and not others.” There are two categories of movement across that semi-permeable cell membrane: passive transport and active transport.
Passive transport across the membrane does not require the cell to expend energy but rather demonstrates the principle that molecules naturally travel from an area of greater concentration to an area of lesser concentration. Oxygen, carbon dioxide, ions, glucose, and water all leave the cell across the membrane along this “concentration gradient.” This scientific phenomenon illustrates the theological principle that “the good is diffusive of itself” (bonum diffusivum sui). The Church has within it the life of God, and that life naturally spills outside the walls of the Church to evangelize the world.
When sinners enter the Church from the world through baptism, the “energy” of Christ’s sacrifice on the cross must be applied to let them in.
Active transport requires the cell to expend energy to bring substances into the cell against the concentration gradient. For example, the cell needs certain minerals to exist in a concentration different from the external environment. Similarly, when sinners enter the Church from the world through baptism, the “energy” of Christ’s sacrifice on the cross must be applied to let them in. As Jesus says, He is the “door; if any one enters by me, he will be saved” and “have life . . . abundantly” (John 10:9-10). In addition to individuals, “the Church receives from the various cultures everything that is able to express better the unsearchable riches of Christ.”8 Through the process of “active transport,” the Church expends the energy of discernment in her work of “inculturation”9 of the life of the cell of the Church.
The characteristics of the Church’s semi-permeable cell membrane can be seen in the practices surrounding Benedictine hospitality: “Saint Benedict commands his monks to be open to the outside world—to a point. Hospitality must be dispensed according to prudence, so that visitors are not allowed to do things that disrupt the monastery’s way of life.”10 Indeed, if the monastic way of life were disrupted completely—if the cell membrane were broken—the monastic community would have no life to offer to the outside world.
To maintain its life, a cell must maintain its membrane. To maintain her existence, the Church must maintain her distinctive identity through her teachings, practices, and laws. Yet like the cell, the Church’s membrane must be semi-permeable, able to let the goodness out and let the sinners in. Evangelization is like movement across a cell membrane.
1 Heather Ayala and Katie Rogstad, General Biology (Camp Hill, PA: Novare Classical Academic Press, 2020), p. 72.
2 Ibid, pp. 78-79.
3 Ibid, p. 89.
4 Michael Behe, Darwin’s Black Box (New York: Free Press, 2006), p. 274.
5 The New Saint Joseph Baltimore Catechism (New Jersey: Catholic Book Publishing Corp., 2011), #136, p. 72.
6 Ayala and Rogstad, p. 89
7 Ibid, pp. 90-94.
8 Pope St. John Paul II, Familiaris Consortio, 10.
9 Ibid.
10 Rod Dreher, The Benedict Option (New York: Sentinel, 2018), p. 73.