Plato vs Aristotle: The Two Opposing Minds Behind Human Thought
And Why We Need Both to Understand Ourselves
Whenever Plato and Aristotle are mentioned, the first thing that comes to my mind is their teacher-student relationship. The intellectual legacy from Socrates to Plato and then to Aristotle has served as a solid foundation for Western philosophy, with their wisdom influencing almost every corner of civilization for over two thousand years and continuing to do so today.
After reading Plato’s The Republic and Aristotle’s Nicomachean Ethics, I was struck by how fundamentally different their philosophies are. Aristotle was undoubtedly one of Plato’s most brilliant students. His excellence, however, was not from his perfection or expansion of Plato’s ideas, as Plato was from Socrates. Instead, Aristotle established his own comprehensive framework for understanding the world, with most fundamentals situated in the opposite direction from Plato’s.
Remarkably, the distinctions of their philosophies have been both antidote and complementary, like Yin and Yang, in shaping the dynamic progress of philosophy, science, culture, and politics throughout history.
Essentially, Plato and Aristotle represent two opposing ways of thinking that the human mind employs. Human civilization has progressed as a result of the constant waves oscillating between the two magnets. As American historian Arthur Herman says:
“For the next two thousand years Aristotle would become the father of modern science, logic, and technology. Plato, by contrast, is the spokesman for the theologian, the mystic, the poet, and the artist.
One gave us a view of reality as multiform and constantly evolving; the other, as eternal and One.
One shaped the contours of Christianity; the other, the ideas of the Enlightenment.”
In this article, I will use two of the most accessible and widely read works by the two great philosophers: Plato’s The Republic and Aristotle’s Nicomachean Ethics, to explore the differences in their fundamentals and the influence each philosophy has had on later generations, specifically, how they represent two modes of thinking that have driven advances in science.
Where is the truth?
In The Republic, Plato, through Socrates’ voice, acknowledges that the physical world perceived by our senses is constantly changing, upon which we can draw opinions but not knowledge itself. Instead, he believes the truth resides in another reality that is perfect, constant, and unchanging. He calls this essence of pure being Form, which is accessible to the philosopher’s mind as the true knowledge. Beauty, virtue, and justice are a few examples of them.
For example, in the world we live in, our faculty of sight perceives the sunlight that leads to nourishment and growth. In Plato’s perfect “intelligible world,” the Form of Good is the source of the sun and exists in the philosopher’s mind as the true knowledge.
In Plato’s view, the physical world is only a shadow or imperfect replica of the world of Forms. This idea is symbolized in his well-known allegory of the cave in Book VII, where ordinary people are likened to prisoners who see only appearances in shadows; the philosopher, on the other hand, escapes the cave and is able to see the real realm and Forms.
Accordingly, understanding the Form of Justice is essential to creating a just city and cultivating a just soul. Since only philosophers can understand what Justice is, Plato leads to the conclusion that only philosophers are qualified to be the rulers of the people.
Moreover, Plato believes there exists the highest Form of the Good as the source of all other Forms. It enables the soul to know and the mind to understand, which becomes the ultimate object of knowledge and the goal of philosophers.
On the contrary, Aristotle rejects the existence of Plato’s separate realm. He believes Form exists within things in the physical world we live in. For example, the Form of a tree is not some ideal “Tree” in another world, but embedded in the structure and nature of the tree itself.
In Aristotle’s view, Form and substance are united in the object itself. More importantly, intellectuals can gain knowledge by studying the world through observations and analysis, but not by escaping it.
Using this principle, Aristotle creates taxonomies of various things in the world, including human psychology, based on his empirical studies. His thorough and precise categorizations are the foundation for his philosophical reasoning, as seen in his views on ethics.
He states that human intellect can be categorized into five types: knowledge, science, practical knowledge, art, and intuition.
He defines the human mind as consisting of rationality and irrationality, with irrationality having two components: one is vegetative, responsible for the body’s nourishment and growth, and the other is “beside the Reason, some other natural principle which fights with and strains against the Reason.” This is perhaps the earliest definition of System 1 and System 2, dating back more than two thousand years.
Furthermore, Aristotle states that the Excellence of Man has two classes: intellectual and moral. The former includes pure science, intelligence, and practical wisdom, and the latter refers to the self-mastery of Virtue.
Similarly, for Happiness, he summarizes three types depending on the context: pleasure from biological life, social life, and intellectual life (“the life of contemplation”). With the belief that the essence (Form) is embedded in this world, he states:
“Chief Good of Happiness must be something which is our own, and not easily taken from us.”
In contrast, his teacher suggests that the Good lies beyond the reach of most people, except for philosophers. Aristotle’s departure from Plato’s view on the separate realm highlights his brilliance as an independent thinker, evident in his sharp observations and clear reasoning.
Ideology vs Action
From the beginning of Nicomachean Ethics, Aristotle emphasizes that Happiness and Virtue are reached through action and execution. Happiness is “the End of executing the soul of Virtue.” And Virtue is manifested through actions.
“We are right then in saying, that these virtues are formed in a man by his doing the actions; but no one, if he should leave them undone, would be even in the way to become a good man.”
He despises those who only talk but with no actions, particularly those who claim they “are philosophizing.”
“Yet people in general do not perform these actions, but taking refuge in talk, they flatter themselves they are philosophizing, and that they will so be good men…”
In Aristotle’s view, everything is a process with a Means to an End. Before reasoning, it is essential to distinguish between the two and how an End can be achieved with possibly different Means. This process-oriented thinking is lucidly demonstrated in his definition of Happiness:
“So then Happiness is manifestly something final and self-sufficient, being the end of all things which are and may be done.”
In other words, Happiness is the End. As such, it can’t happen itself, but through the means of actions.
For Plato, he is more keen on how to get the truth into the minds of philosophers, though he doesn’t know how. Socrates admits that, even as a philosopher, he will likely never reach it, but rather arrive at a close approximation. The debates between Socrates and those around him center around the discovery of the truth that should have already been in their minds. In Plato’s view, once the discovery is made, actions should automatically follow.
Aristotle recognizes the complexity of how a person can act to achieve the right outcome — correct reasoning in the mind alone doesn’t guarantee the right action or result. Using these observations, Aristotle delves deeply into human nature, examining the conflicts between voluntary and involuntary wills, rationality and compulsion, and various states of moral choices.
By dividing Excellence into intellectual and moral aspects, he argues that the former requires teaching, while the latter must be practiced and developed into a “custom” or habit. According to Aristotle, the means for humans to achieve their goals are through learning, practice, and action. He says:
“Men must do just actions to become just, and those of self-mastery to acquire the habit of self-mastery.”
Moreover, Aristotle taps into humans’ decision-making process, stating that rational Deliberation ultimately leads to a just decision.
“For a man engaged in a process of deliberation seems to seek and analyse, as a man, to solve a problem, analyses the figure given him. And plainly not every search is Deliberation, those in mathematics to wit, but every Deliberation is a search, and the last step in the analysis is the first in the constructive process.”
Finally, Deliberation is united with action to achieve the goal chosen by will.
“So it seems, as has been said, that Man is the originator of his actions; and Deliberation has for its object whatever may be done through one’s own insrumentality, and the actions are with a view to other things; and so it is, not the End, but the Means to Ends on which Deliberation is employed.”
Remarkably, back in ancient Greece, Aristotle had already accurately described the entire human decision-making process, typically consisting of assessment, options, evaluation, and action selection, as we understand it today.
Top-Down vs. Bottom-Up Thinking Processes
Besides where the Form resides, another key difference between Plato and Aristotle is in their approach to discovering the truth.
Aristotle emphasizes that empirical observations are crucial in establishing the correct premises for reasoning. He begins with direct experience, observations, and experiments. Next, he uses deductive reasoning (especially the syllogism) to build scientific knowledge.
In contrast, Plato believes humans can reach the truth through pure reasoning and that knowledge is already present but hidden within people’s minds. A philosopher’s task is to discover it through logical inquiries, as exemplified by Socrates’ dialectic method.
The approach, however, is limited without new evidence or gathering more facts, as English philosopher Bertrand Russell points out in his book The History of Western Philosophy:
“The dialectic method — or, more generally, the habit of unfettered discussion — ends to promote logical consistency, and is in this way useful. But it is quite unavailing when the object is to discover new facts.”
Simply put, Plato’s philosophy is a typical “top-down” approach in Western philosophy. Many philosophers have followed Plato in believing they can use their own reasoning to find the truth governing the world.
In earnest searches for true knowledge from another realm, Plato’s philosophy ends up with either seeking the ultimate creator beyond the current reality, or attempting to recreate a new reality from scratch, based on what is in the philosopher’s mind. Unfortunately, humankind has repeatedly experienced the pain when an ideal clashes with brutal reality.
In contrast, Aristotle takes a “bottom-up” approach. He based his conclusion on empirical observations and verifications through real-world scenarios and conditions. Instead of following a top-down blueprint, he starts by observing the surrounding reality. His approach is a scientific one: first, collect the data through experiments, then analyze, and finally draw a conclusion.
In his book Nicomachean Ethics, Aristotle was already a scientist at heart:
“Again, we think Pleasure must be in some way an ingredient in Happiness, and of all Workings in accordance with Excellence that in the way of Science is confessedly most pleasant: at least the pursuit of Science is thought to contain Pleasures admirable for purity and permanence; and it is reasonable to suppose that the employment is more pleasant to those who have mastered, than to those who are yet seeking for, it.”
Aristotle’s empirical approach grounds his ethical concepts in human nature and social life. He realizes that an individual can’t live without others, and friendship is the social relationship that is essential for human happiness. For an ideal society, what he sees first is an individual, the essential building block of every political community. To make the community good, we should first ensure each individual is happy, but not the other way around.
So whose approach is better?
Plato and Aristotle Represent Two Opposing Modes of Human Thought
Plato and Aristotle represent two distinct ways of thinking that permeate every corner of today’s society. Plato focuses on ideologies that are eternal and perfect, seeking ways to control human society through the highest Form of justice, virtue, and order, in a top-down approach. No wonder his philosophy paved the path for the Christian tradition, emphasizing spiritual ideals and transcendence over the physical and ever-changing reality.
Today, we know there is no such perfect realm beyond the world we live in. The ideals and abstract perfections arise from within our minds. As stated in the previous article, the brain is fundamentally a predictive machine, equipped with curiosity, imagination, and the drive to solve problems and plan to reach goals.
One type of a perfect idea (Form) is the pure logic among numbers and geometrical figures. Similar to how artists draw inspiration from muses, their sudden revelations to the mind make one think they must come from an external source. As Austrian-Irish theoretical physicist Erwin Schrödinger says in one of his essays:
“A mathematical truth is timeless, it does not come into being when we discover it. Yet its discovery is a very real event, it may be an emotion like a great gift from a fairy.”
Moreover, Plato’s allegory of the cave has been supported by contemporary neuroscience and psychology. Our perception of the world is not a faithful representation of the physical world. Rather, it results from complex interplays of sensations and constant mental predictions based on previous experiences, which can be illusory, like the shadow in the cave.
Conversely, our ideas are not trustworthy as Plato thought because they tend to be biased easily, as opposed to being perfect, particularly by our subconscious, which is not accessible to the rational mind.
No matter how beautiful or elegant a theory appears, it remains a hypothesis until it is tested and verified in real-world scenarios. Aristotle’s philosophy on empirical and experimental studies is precisely what is needed to tell the truth from falsehood.
Ultimately, over two thousand years of history have taught us that human civilization requires both Plato’s top-down idealism and Aristotle’s bottom-up empiricism. The former inspires innovation, reformation, and even revolutions (e.g., the Renaissance), enabling people to break free from a dire situation. The latter leads to steady improvements and progress. Without the former, however, the latter could lead to complacency of accepting the status quo and over-rationalizing the current situation.
The same is true in science. As American historian and philosopher Thomas Kuhn pointed out in his book The Structure of Scientific Revolutions, scientific progress is not linear, resulting from a steady buildup of knowledge. Instead, he argues that science advances through a series of scientific revolutions, marked by fundamental paradigm shifts. Here, a paradigm is a comprehensive theory that reinterprets existing data and offers a new framework for understanding the world.
The well-known examples occurred in physics. In 1543, Nicolaus Copernicus rejected the traditional view that the Earth is at the center of the universe. Instead, he proposed that the Sun is at the center, with Earth and the planets orbiting around it. His theory was later confirmed as correct by prominent scientists such as Kepler, Galileo, and Newton, marking the beginning of the “Copernican revolution.” The Copernican model led to a complete rethinking of humanity’s place in the universe and the nature of motion and physics.
Obviously, a more recent scientific revolution was brought by Einstein. Before him, Newton’s mechanics theory had been valid for centuries and successful in explaining planetary motion and everyday physics. Specifically, in his theory, space and time are considered absolute, and gravity is a force that acts at a distance between masses.
At the beginning of the 1900s, with his relativity theories, Einstein predicted that space and time are relative and form a four-dimensional space-time continuum. And gravity is not a force but the curvature of space-time caused by mass and energy. His theories completely transformed humans’ understanding of space, time, and the universe.
In both examples, Copernicus and Einstein developed their new theories in their minds, using deductive logic and elegant mathematical equations. It is precisely how Plato sought to find the truth. Later, their theories were tested and confirmed by scientists through empirical experiments and observations. Both Plato’s top-down and Aristotle’s bottom-up thought processes complement each other in the history of science, driving progress over the centuries.
Finally, we turn to the study of the human mind and consciousness.
Back in 1979, Nobel Laureate Francis Crick, who deciphered the genetic encoding of DNA, published an essay in Scientific American titled “Thinking about the Brain,” in which he made a stark observation of the state of neuroscience:
“In spite of the steady accumulation of detailed knowledge, how the human brain works is still profoundly mysterious.”
He then pointed out:
“What is conspicuously lacking is a broad framework of ideas in which to interpret these results.”
Today, his vision is more relevant than ever. Over the past decades, neuroscientists have made tremendous progress by collecting a vast amount of experimental data using advanced techniques and clever methods. However, the precise mechanisms behind the brain functions, especially those responsible for behaviors, emotions, intelligence, and consciousness, remain elusive and highly perplexing.
Seemingly, what the field needs is a revolutionary paradigm shift, similar to the one that occurred in physics — a comprehensive theory that unites the numerous scattered concepts to explain the massive amount of data, and makes predictions to guide future research.
Today’s artificial neural networks and AI enable the simulation of thousands or millions of interconnected artificial neurons. Additionally, they have demonstrated human-like learning abilities and intelligence. Their ongoing progress could inspire and support new brain theories in a way that was previously impossible.
Many scientists and engineers have already seen the necessity and the opportunity. We are in an exciting era where an infusion of Platonic top-down idealism might lead to a breakthrough in understanding the brain’s underpinnings.
In Raphael’s famous fresco, “The School of Athens,” Plato and Aristotle are positioned at the center. Plato, with his finger raised upward, symbolizes the pursuit of ideal and transcendent realities. In contrast, Aristotle extends his right arm forward, emphasizing his keen interest in human interactions with the physical world.
Raphael, at the height of the Renaissance (five hundred years ahead of us), had obviously recognized their differing philosophies and profound influences. The painting is a classical example showing why their philosophical ideas have been timeless and will continue to shape humans’ understanding of the world and ourselves.