Aristotle, Evolution, and the Four Causes
Understanding How Definitions Inform Understanding
Introduction
What does it mean to say that something is true? What makes an explanation meaningful rather than shallow? In the heart of classical philosophy, and firmly within the Catholic intellectual tradition, stands Aristotle, whose profound insights continue to shape how we understand the natural world. Thomas Aquinas referred to Aristotle as “the philosopher” because he sought understanding the thing for what it is: the essence, the purpose, the parts, and the whole.
As Catholics, we believe that faith and reason, far from contradicting each other, work together to illuminate truth. This includes the truth about the created order: its purpose, beauty, and intelligibility.
This article brings Aristotelian philosophy into dialogue with modern evolutionary theory, showing how a classical understanding of nature, one that includes purpose (final cause) and form (formal cause), enriches our view of life’s development. Along the way, we offer age-appropriate activities, discussion questions, and prompts for deeper investigation.
We are more than a sum of our parts: which is something that even some evolutionary biologists are beginning to discuss.
Foundational Ideas: Aristotle and the Four Causes
Unlike modern systems that often isolate phenomena into narrow frames (material, empirical, or mathematical), Aristotle offers a comprehensive framework that respects both the physical world and the metaphysical realities that give it coherence. Aristotle’s logic begins with the principle of non-contradiction: something cannot both be and not be at the same time in the same way. Aristotelian philosophy remains a firm foundation for judging logic because it is rooted in the nature of being itself and seeks to understand not only what things are, but also why they are.
From this flows a rich tradition of syllogistic reasoning, definition, classification, and demonstration: designed not merely to manipulate symbols, but to reflect truth about reality. Here's a simple example illustrating the Aristotelian principle of non-contradiction, which states that “the same attribute cannot at the same time belong and not belong to the same subject in the same respect.”
Example: Let us consider a door. At a given moment, we assert: “The door is open.” If we also say, “The door is not open,” at that same moment, in the same way or respect (i.e., physically), we have violated the principle of non-contradiction. It cannot be both open and not open at the same time in the same respect.
However, if we say: “The door is open physically,” and “The door is not open to discussion,” then we are not contradicting ourselves, because the respect differs: one is physical openness, the other metaphorical. This principle is foundational because, without it, reasoning itself dissolves into absurdity. Truth would become indistinguishable from falsehood.
This principle undergirds rational thought.
At the heart of Aristotle’s method is his doctrine of the Four Causes, which provide a full account of why a thing is the way it is:
1. Material Cause – What is it made of? This refers to the substance or matter from which a thing comes. Example: A statue’s material cause is the marble.
2. Formal Cause – What gives it its form or essence? This is the pattern, structure, or nature that makes a thing what it is. Example: The shape or idea of the statue—the design in the sculptor’s mind.
3. Efficient Cause – Who or what brings it into being? This is the agent or force that produces the change or motion. Example: The sculptor carving the marble.
4. Final Cause – What is its purpose or end (telos)? This is the reason for which a thing exists—the end toward which it tends. Example: The statue exists to honor a hero or to express beauty.
Aristotle argues that to understand anything fully, one must consider all four causes. Modern science often limits itself to material and efficient causes, which gives it power but also renders it blind to meaning and purpose. In this way, Aristotelian philosophy doesn’t merely supply rules for valid thought, but invites a vision of reality in which truth is knowable, nature is intelligible, and reasoning is ordered toward wisdom.
Why This Matters for Science and Faith
Modern science often limits itself to material and efficient causes: what things are made of and how they came to be. While this makes science powerful and testable, it can miss deeper questions about meaning and purpose. Evolutionary theory, for example, has explained many processes of biological change. But without integrating Aristotle’s four causes, especially the final cause, the story of life is left unfinished.
While there are many definitions of evolution, one of the most commonly accepted definitions is: “Evolution is the change in the heritable traits of a population over successive generations.”
This definition is both accurate and non-controversial. It is rooted in observable science (e.g., genetics, laboratory studies). It makes no metaphysical claims about origins or purposes, only about change over time. It is precise: “heritable traits” refers to genes passed from parent to offspring; “populations” distinguishes evolution from individual development. This definition can be embraced even within faithful worldviews that affirm God as Creator, for it observes how life diversifies and adapts without pronouncing upon its ultimate cause.
However, from an Aristotelian perspective, this definition is incomplete. Aristotle would ask not only what changes and how, but what is the nature of the thing changing, what is the form it tends toward, and what is its end (telos). He would insist on including formal and final causes, lest the explanation be shallow or fragmentary. With Aristotle’s philosophy in mind, I propose a richer understanding of evolution:
“Evolution is the process by which living beings, according to their nature and in response to their environment, undergo change in form and function across generations, guided by both internal principles of development and external conditions, ordered ultimately toward the flourishing and perfection proper to their kind.”
This reframes evolution not as random genetic shuffling, but as a process grounded in nature’s intelligibility, respecting the unity of form, purpose, and adaptation. It leaves room for secondary causes, contingency, and even divine providence, without falling into mechanistic determinism or materialist reductionism.
The Theories of Evolution, Not the Theory of Evolution
The story of evolutionary theory is not one of a single, unchanging idea, but of a gradual development and refinement of ideas over time. From its earliest forms to the present day, the theory of evolution has grown in complexity as scientists have sought to explain the diversity of life on Earth through observation, experimentation, and inference. Each stage in this development reflects not only new discoveries, but also new questions about life, purpose, and the mechanisms that shape living organisms.
The first widely discussed theory of evolution was proposed by Jean-Baptiste Lamarck in the early 19th century. Lamarck suggested that organisms could pass on traits they acquired during their lifetimes to their offspring. For example, he believed that giraffes stretched their necks to reach high leaves, and that this effort caused their necks to lengthen—changes that were then inherited by their young. This idea, called the inheritance of acquired characteristics, was an early attempt to explain how species might change over time, though it lacked the mechanisms we understand today through genetics.
Later in the 19th century, Charles Darwin proposed a more influential theory in his book On the Origin of Species (1859). Darwin introduced the idea of natural selection, the process by which individuals with traits better suited to their environment are more likely to survive and reproduce. Over many generations, this can lead to the development of new species. Darwin’s theory emphasized gradual change and variation within populations, but it was missing a key element: a clear understanding of heredity. That gap would not be filled until the early 20th century.
The Modern Synthesis, developed in the 1930s and 1940s, merged Darwin’s theory of natural selection with Mendelian genetics, which is the study of how traits are inherited through genes. This synthesis provided a more robust explanation for evolution by showing how genetic mutations could introduce variation, and how natural selection could favor some traits over others. It became the dominant framework for understanding evolution throughout the 20th century.
However, not all evidence fit neatly into this model. In the 1970s, paleontologists Stephen Jay Gould and Niles Eldredge proposed Punctuated Equilibrium, a theory suggesting that evolutionary change does not always occur slowly and steadily. Instead, species often remain stable for long periods, interrupted by brief, rapid bursts of change. They posited that this sudden burst is often tied to major environmental shifts or population isolation. This challenged the gradualism of earlier models and opened the door to considering more dynamic patterns in the fossil record.
In more recent decades, scientists have explored how developmental biology shapes evolution. Evo-Devo, short for Evolutionary Developmental Biology, studies how changes in the development of organisms, especially during early growth stages, can lead to major evolutionary differences. It highlights the role of genes that control body plans, such as Hox genes, and shows how small genetic changes can produce large morphological effects, like the difference between limbs and fins.
Finally, the Extended Evolutionary Synthesis (EES) is an ongoing effort to broaden evolutionary theory even further. It incorporates insights from systems biology (which studies complex interactions in biological systems), epigenetics (which looks at how gene expression can be influenced by the environment without changing the DNA sequence), and other fields. The EES seeks to explain how organisms and their environments interact in a more integrated way, offering a richer account of inheritance, adaptation, and innovation in living systems.
These theories are not necessarily in conflict, but rather represent a growing attempt to understand life more completely. As scientific knowledge deepens, so too does the challenge of interpreting what it means to be alive, to change, and to exist with purpose. These are questions that touch not only on biology, but also on philosophy and theology.
Grade-Level Explorations
Grades K–3: Wonder and Order in Creation
Children at this age are full of wonder. Introducing them to the natural world is the beginning of teaching them to see God’s order and beauty in creation. Rather than focusing on abstract theories, we invite them to notice patterns, ask questions, and connect what they see with the truth that God is the Creator of all things.
Activity:
Observe and draw three plants or animals in your backyard.
What are they made of?
What shape do they have?
Who made them?
What are they for?
Discussion Questions:
Can something be a plant and not be a plant at the same time?
Why do flowers bloom? Is it just to look pretty?
Who made the world, and why?
Further Investigation:
Read Genesis 1 and draw pictures for each day of creation.
Learn the names of your local trees and their uses.
Call to Action:
Talk with your family about how God’s creation shows His order and purpose.
Grades 4–6: Reasoning and the Four Causes
As children grow in logical thinking, they begin to ask deeper questions—“why” and “how.” This is the right time to introduce Aristotle’s Four Causes:
Material Cause – what something is made of
Formal Cause – its shape or structure
Efficient Cause – who or what made it
Final Cause – its purpose or end
By applying these causes to both nature and what they create, students begin to see that everything, from a pinecone to a paper airplane, exists for a reason.
Activity:
Build something from Lego or clay. Then identify the Four Causes:
What is it made of?
What design did you use?
Who made it?
What is it for?
Discussion Questions:
Can you think of something in nature that has a purpose?
What’s the difference between saying something happens “by chance” and “for a reason”?
Further Investigation:
Read a short story of a scientist (e.g., Darwin’s finches) and ask: What were they trying to discover? What questions did they not ask?
Call to Action:
Begin a nature journal. Record what you see, and ask, “Why is this here?”
Grades 7–9: Evolution and Its Limits
Introduction:
As students encounter scientific theories, they are ready to critically evaluate different perspectives. Two major evolutionary theories are:
Lamarck’s theory: Organisms change because of use or disuse of traits, and these traits are inherited (e.g., giraffes stretched their necks and passed it on).
Darwin’s theory: Species evolve by natural selection—random mutations are filtered by environmental pressures, favoring traits that improve survival.
Both theories attempt to explain biological change but often omit the formal and final causes. Aristotle’s full view reminds us that nature is not only about mechanisms but also meaning.
Activity:
Research Lamarck’s and Darwin’s theories. Create a comparison chart showing:
Strengths
Weaknesses
Compatibility with Aristotle’s Four Causes
Discussion Questions:
What causes are missing in most evolutionary explanations?
How does including formal and final causes change the way we think about life?
Is science enough to answer questions of purpose?
Further Investigation:
Read excerpts from On the Origin of Species and summarize how Darwin uses observation.
Watch a video on Evo-Devo (Evolutionary Developmental Biology). Write a response: What parts seem Aristotelian?
Call to Action:
Write your own definition of evolution that includes Aristotle’s insights.
Grades 10–12: Integrating Faith, Reason, and Science
Introduction:
Older students are ready to grapple with the complexity of evolutionary theory and the tension, or harmony, between science and faith. They should explore modern theories such as:
Modern Synthesis – combines genetics with Darwin’s natural selection.
Punctuated Equilibrium – evolution occurs in rapid bursts rather than gradual change.
Evo-Devo – emphasizes the role of developmental processes in shaping evolution.
Extended Evolutionary Synthesis (EES) – expands evolutionary theory to include systems biology, epigenetics, and more.
Each theory focuses on mechanisms but often neglects questions of form, purpose, and design. Aristotle’s Four Causes, paired with Catholic teaching, help integrate truth from revelation with truth from reason, showing that faith and science are not enemies but allies in seeking the truth.
Activity:
Choose one evolutionary theory (Modern Synthesis, Punctuated Equilibrium, Evo-Devo, or EES).
Analyze it using Aristotle’s Four Causes and present your findings.
Discussion Questions:
Does modern evolutionary theory provide a full explanation of life?
Can science and faith be in harmony? Why or why not?
What does it mean to say that nature is “ordered toward an end”?
Further Investigation:
Read parts of Fides et Ratio (Pope St. John Paul II) or In the Beginning (Pope Benedict XVI).
Write an essay: How does Aristotle help a Catholic understand evolution differently than a materialist?
Call to Action:
Share your reflection or presentation with your parish youth group or class.
Conclusion: Truth is One
Truth is never in conflict with itself. As Catholics, we affirm that science and philosophy, when rightly understood, cannot oppose faith. Aristotle's philosophy helps ground science in a rational, meaningful world; one where order, purpose, and beauty point to a Creator. Evolutionary theory, stripped of metaphysical confusion and reintegrated with classical wisdom, can invite us into deeper wonder at God’s providence.
Let’s raise up students, young philosophers and scientists, who seek truth boldly, reason clearly, and worship joyfully.
Share and Discuss: Forward this to Catholic educators, parents, and students. Host a book club or philosophy circle in your homeschool or parish. Begin with Aristotle’s Physics or Metaphysics and build bridges between science and the soul.
Gloria Dei vivens homo.