Circular Order in Biology

There are many kinds of order in the realm of living things. Some, like day and night and the four seasons are so obvious we hardly think of them as systems of order. What are some of the other systems of order? Where does the order in each instance come from? What is the relation between the lower orders and the higher ones? Does this order point to something beyond itself, a principle of the overarching order in nature? 

I will begin by describing my experience of three systems of order: day and night; the four seasons; and the habitats. I will then reflect on the circular order in each of these systems. Next, I will look at hierarchy within these systems. Then I will look at the harmony in nature as a whole. I will explain the different ways creatures are ordered to an end in nature. Finally, I will look for a principle that unifies all these systems: the circular order of the Trinity as origin and archetype.

Day and Night

At dawn in the summer, I step out on our deck to hear hundreds of birds singing from the spruce trees behind our garden. During the day scarlet cardinals, titmice, black-capped chickadees, and blue jays flock to our feeder. Chipmunks and squirrels emerge from their trees or holes to eat sunflower seeds below our feeder. Such diurnal animals are active in the day and sleep at night. They need light to find their way to food and to avoid enemies. At dusk, deer emerge from the woods to eat the apples below our tree. I have counted as many as seventeen deer coming to drink by the river below our house. Later they will hunker down to rest behind clumps of bushes in our neighborhood or back in the woods.

At night, the owls, bats, foxes, raccoons, and opossums come out to feed. Such nocturnal animals are active at night and sleep in the day. We have had quite a battle with the raccoons over our bird feeder. At midnight, I have watched an enormous raccoon shinny up the feeder pole, climb over the cone-shaped baffle, and grab the seeds, sometimes knocking off the whole feeder. Humans also conform to this cosmic rhythm. We rise with the sun and work during the day and then tire out and rest at night. The dusk is like a curtain that calms the busyness of the day and prepares the restfulness of family dinner, prayers, reading, and sleep.

Four Seasons

The robins arrive first, announcing the spring. The leaves bud in the spring, grow big and green in the summer, turn gold, red or brown in autumn, then fall in the winter. We have bare trees and snow in the winter, but also red holly berries and many red cardinals at the feeder. Animals also conform to this rhythm: generation and birth in spring, growing in summer, maturing in the fall and many dying or hibernating in winter. 

Numerous migrating birds like warblers and ruby-throated hummingbirds arrive in the Spring to join the year-round residents, courting, building their nests, and raising their fledglings. We add two sugar water feeders in the spring for the many hummingbirds. The noise of the birds singing is most intense in the spring as are the colors of their plumage. Other birds like gold finches and Baltimore orioles only stay a few days and fly further north. We see many does with one or two fawns and even rabbit does with kits. One evening we saw eight baby foxes playing in our yard, chasing each other around the spruce trees.

In summer, green leaves cover the trees and hide much of the animal activity. The birds and mammals are busy feeding their young and storing up food for winter cold or migration. No vegetable garden or young tree is safe from their predation. (My neighbors have contrived various nets and fences and have even added whirligig spinners to try to keep out the deer and rabbits.)

God gives being to creatures so that they can receive a share of his goodness and joy, but only intelligent creatures can completely receive the gift of being since they are the only ones who can consciously possess their being and understand it as a gift from God. 

In fall, we hear the wild call of the Canadian Geese as they fly overhead on their way South. Golden leaves float down from the tall trees by the river as I walk. They transform the road and the river into paths of gold. The chipmunks and squirrels are busy collecting and hiding acorns, walnuts, and seeds. Blue jays are frequent visitors at the feeder, taking away masses of seeds to hide in their pantry trees.

In winter, there are still many birds at the feeder although the hummingbirds and warblers are gone until late spring. The squirrels and rabbits are mostly invisible, hibernating in their nests or holes. Once, I was delighted to see the pert head of a chipmunk poke up from a deep hole in the snow under the feeder. He had tunneled a runway in the snow to the feeder. The deer leave their hoof prints in the snow when they come at night and eat the seeds under the bird feeder and any green plants left in our garden. Each plant and animal lives by and for its activities of day and night, spring, summer, fall, and winter. They grow, nourish themselves, and reproduce in their own characteristic way. A bird flies to find food and live, but it also lives to fly. Flying is part of what makes it good to be a bird.

Humans have their own lifetime rhythm that mirrors nature’s seasons. Infancy, youth, courting, and marrying are like our spring. The summer is the time of raising and educating our children, fall is the peak time of our work when the children begin to leave home for college and marriage. Winter is the time of aging and dying. The four seasons are good metaphors for the seasons of our life.

Habitat

In the Sonoran Desert, where I spent my childhood, the dominant characteristics are aridity and extreme heat in the summer. The Sonoran Desert is an iconic habitat, a place where a characteristic physical feature determines which plants and animals can live there. The principal plants in the Sonoran Desert are saguaros and other cacti which have no leaves in order to retain water. Their stems are enlarged and green, performing the photosynthesis usually done by leaves. There are few animals, many of whom live in holes in the ground during the heat of summer days. The animals often need little or no water but get their hydration from the plants they eat such as prickly pear cacti which have juicy round stem segments as well as fruit. 

All habitats have a food chain, beginning with plants, which are the producers, making food by photosynthesis. In the woodland habitat by our house in Ohio, the producers include sycamores, oaks, black walnuts, and many ferns and grasses. The first-order consumers like insects, birds, mice, and squirrels, eat the seeds, and leaves. Although deer are so much larger, they are also first-order consumers eating only plant matter. Second-order consumers like hawks, owls, snakes, racoons, foxes, and weasels feed on the first-order consumers. They are not large enough to feed on deer. There are few third-order consumers like wolves and bears in our woods that would feed on the second-order consumers as well as large first-order consumers like deer. This leads to overpopulations of deer and of some of the second-order consumers. Finally, when animals and plants die and decay, the decomposers like earth worms, beetles, and snails break down dead animals and plants into smaller pieces. Then the bacteria and molds decompose the remains into essential nutrients which are returned to the soil. They enrich the soil so that it can again nourish the plants that are the producers of the circular food chain. Each habitat has a different group of plants and animals and decomposers that form a circular food chain which is connected to the water and mineral cycles. Without these cycles the habitat would collapse.

Circularity 

The repetition of day and night and the four seasons makes these two systems circular. The repetition is caused by the light and heat of the sun, the natural principle of life on Earth. Day follows night and returns, following the rotation of the earth as each hemisphere faces the sun again. Spring, summer, winter, and fall repeat themselves because of the tilt of the Earth as it revolves around the sun. Even food chains in habitats have a circularity, the first step of which is always caused by the sun. Plants, using minerals from the soil, water and sunshine to make sugar, are the beginning of every food chain. 

Hierarchy

The top predators in every habitat are also usually the most intelligent. Bears have strong memories, are good at problem-solving, and finding food sources. Wolves excel in communication and teamwork. They hunt in packs and have a strict social order. Deer, first order herbivores, exhibit little problem-solving or elaborate social life. There is a hierarchy among the organisms in habitats. But what criteria besides intelligence allow one to determine that one being is higher than another? 

Few would doubt that plants are a higher kind of being than rocks. Plants and other living things have unity and self-motion. They nourish themselves, grow and develop themselves into adults, and reproduce. They must constantly metabolize, act for their own sake, or die. Non-living things just exist. They do not act for their own sake. Chip a rock and it will not defend itself. Among living things, animals have a richer way of life than plants because they can sense and form some picture of the world around them. They have desire and fear. They move towards what they desire and flee what they fear. The higher the animal, the more complex the picture it has of the world and the more complex its relations can become to what is outside itself. Higher mammals and birds remember where even distant food sources are located, develop courtship and parenting behaviors as well as social hierarchies. Some mammals can use tools like sticks to draw insects out of holes so they can eat them. Higher mammals and birds are more intelligent than lower.

Man alone has reason. His mind can come into relationship with all of reality, including the Creator. Lower animals cannot even notice things that do not immediately pertain to their biological life. Even dogs do not look up and wonder at the starry heavens. Man is the only bodily creature that can recognize his life as a gift from God. Hence Gaudium et spes states, “…human beings are the only creatures on earth that God has willed for their own sake.” All lower creatures exist to serve man, at least to provide the universe in which he dwells. The universe would make no sense without man. It would be like a body without a head. However, this does not mean that infrahuman creatures are simply useful goods. Each creature has its own good which it can enjoy in some limited sense; each creature gives glory to God even if no human notices it. Ten thousand brightly colored butterflies in the Metazoan era, millions of years before humans existed on earth, would still be beautiful, and give God glory. However, humans are the summit of material creation. Thus, there is an order of nobility like a ladder among the organisms of earth from amoebas to humans.

Harmony of Nature

The existence of a hierarchy of different kinds and levels of natural beings means that they can form an ordered whole. Many similar things do not lead to unity but just to multiplicity. A million grains of sand just make a pile; their only unity comes from being adjacent to each other, a meager accidental unity. Just as there could not be a forest habitat without soil, a stream, trees, animals and bacteria, the Earth could not exist as a kind of whole without many habitats and many webs of relationships between all the creatures of nature. Oceans, winds, and mountains control weather and make possible different habitats in different areas. Organisms on earth interact in many ways not only with each other but also with their environment and even regulate it in ways that promote conditions that support life. “God wills the interdependence of creatures…. Creatures exist only in dependence on each other, to complete each other, in the service of each other” (CCC 340). 

But this harmony in nature also has an extrinsic good, namely, to represent God’s goodness. Two kinds of order are at stake here. One is the order of a whole and its parts; the other is the representation of God’s goodness for the glory of God. This second type of order closes a circle by being a kind of return of Creation to God from whom it came. Each creature mirrors God’s goodness in its own way, but the whole does so most perfectly. At the end of the creation narrative, Genesis tells us, “And God saw everything that he had made, and indeed it was very good.” 

Rational creatures attain God in a more perfect way. They can know and love him. Man serves lower creatures by wondering at the beauty of the world and its inhabitants. 

The running stream cannot marvel,
and silently the woods slope down,
following the rhythm of the stream—
but man can marvel!
The threshold which the world crosses in him
is the threshold of wonderment.
(Once, this very wonder was called “Adam”).

He was alone in his wonder,
among creatures incapable of wonder—
for them it is enough to exist and go their way.
Man went his way with them,
filled with wonder![1]

Humans can preserve creatures in memory and love. They can become the voice of the cosmos in praising God. “Bless the Lord, sun and moon; sing praise to him and highly exalt him forever” (Dan 3:62). This leads to a new kind of circular order. Everything is called into being by God and all creatures on earth are given back to their source, the Creator, when humans praise and thank God for their beauty. This is the circular order that is the cause of creation. 

A Recapitulation: Five Levels of Ends

We have looked at five ends in the universe. First, we considered organisms pursuing their own manifold activities during day and night and the four seasons. They exist both by and for these activities. Second, we considered how lower organisms exist for the sake of higher in habitats. Plants also exist so that animals will have food. Third, we saw that all creatures exist for the perfection of the whole as all plants and animals as well as the elements and man exist for the harmony of nature. Fourth, we saw that the whole also exists for an extrinsic good, namely, to represent divine goodness for the glory of God. Fifth, rational creatures have in a special and higher way God as an end, imperfectly in the present by knowing, loving, and praising him, and more perfectly in the beatific vision, their final end.[2] The representation of God by the universe is completed in humans and angels making a conscious personal return to God in knowing and loving him. This return in knowledge and love allows the universe in its principal members to imitate the personal communion in the Trinity.

The Circular Order of the Trinity as Origin and Archetype

In the Trinity, the Father lovingly begets the Son, and the Son returns to the Father, both by reflecting him perfectly as his Image, and in loving him perfectly in the Holy Spirit whom he breathes forth together with the Father.

In De potentia, St. Thomas writes about the circle of love in the Trinity:

The Holy Spirit both proceeds from the Father into the Son, and from the Son into the Father, not indeed as into a recipient, but as the object of love. For the Holy Spirit is said to proceed from the Father into the Son, inasmuch as he is the love by which the Father loves the Son; and for a like reason, it can be said that the Holy Spirit [proceeds] from the Son into the Father, inasmuch as he is the love by which the Son loves the Father.[3]

The Father and Son are united in their bond of love, who is the Holy Spirit. The procession of the Holy Spirit is the circular movement of Father and Son toward each other, completed in each other in the person of the Holy Spirit. The communion of love is the unity of the circular order of the Trinity; it is a result of the self-gift of the processions. This life is perfect blessedness; nothing is lacking; nothing more is required.

Why then does God create? Why should God’s goodness overflow outside himself in the production of creatures since there is already a perfect communication of goodness within the Trinity? God’s communication of himself in creation is essentially liberal; He needs nothing from creatures; they can add nothing to his perfect goodness. Liberality is something greater than self-interest; it is fitting for the Supreme Being who is Supreme Goodness to give without need, simply to share his goodness and joy. God gives being to creatures so that they can receive a share of his goodness and joy, but only intelligent creatures can completely receive the gift of being since they are the only ones who can consciously possess their being and understand it as a gift from God. Therefore, only intelligent creatures are willed by God for their own sake. 

God permits Creation to participate in the circular movement of its procession or exitus “out from” God into being and then in its return (reditus) back to God in reflecting his beauty, goodness, and wisdom in its manifold natures and systems of order but most perfectly in the love and praise for him and all his works by men and angels. This enables us to look at all the natural systems of order on earth as reflections of the ultimate circular order in the Trinity. The repetition of day and night, the four seasons, and the food cycles in habitats are already images. The hierarchy of organisms, summed up in man, and returned to God in his knowledge and love is a closer image. But the whole of nature, with its unity and harmony, caused by the interdependence of creatures, is the most perfect being that exists. All the other systems of order like day and night, the four seasons and the habitats bring forth and constitute the harmony of nature. Even humans and angels as the apex of the hierarchy belong more to the common good of the universe than to themselves. Therefore, angels’ and man’s return to God in love and praise for him and his creation belongs not only to them but to the universe. This return of the universe is most like the circle of love in the Trinity in which the Son comes forth from the Father and returns to the Father in the Love of the Holy Spirit.