Introduction

Many cultures have stories of ancestors who had beliefs about how the universe came into being and how people were created. These are genesis stories or origin stories. Philosophers have suggested their own explanations, hoping to use logical arguments to help find the best reasons to discover and believe the truth about the universe’s origins. The ancient Greeks, in particular, offered many different explanations for the universe, and many of those views were very different from the creation stories offered by the religions of the world. Many of those ideas, philosophical and religious, ended up in the great libraries of the ancient world, and people like Plato and Aristotle read, taught, and wrote about them. In fact, one of the titles of Aristotle’s books is Metaphysics.

Both Plato and Aristotle thought and wrote about first causes and unchanging things. To oversimplify, Plato suggested that the world we live in (which is full of imperfections and things that change) is a kind of reflection of a more real, more perfect, unchanging world that we can’t see. From a certain point of view, that other world is a kind of cause of the one we live in. And, to continue with the oversimplification, Aristotle suggested something that sounds scientific today (which is saying something because science, as method, didn’t get introduced for about 2,000 more years): he observed that everything in the world that moves was moved by something else. And this led him to wonder about the first thing that moved.

Metaphysics before Plato

Before Plato, early Greek philosophers, often called the Pre-Socratics, laid the groundwork for metaphysical thought. These thinkers were trying to find the primary substance or principle that was the foundation of everything else. Thales, for instance, thought that water was the underlying substance of everything. Anaximenes suggested it was air, and Heraclitus argued that fire and change were the keys to understanding the universe. Parmenides thought Heraclitus was wrong about that, and he said that change was actually an illusion, and that reality itself is a single, unchanging thing.

Thales is often identified as the first philosopher, especially in the Western tradition which focuses on the contributions of the Greeks. He proposed that water was the substance that gave rise to everything else. He argued that water is essential for life, that it is present in all the forms that matter appears (solid, liquid, and gas), and noted that many living things are sustained by moisture. He believed that since water is crucial for life and exhibits transformative properties, it must be the fundamental principle of all matter.

Anaximander, we think, lived at the same time and in the same place as Thales. Anaximander has the distinction of being the earliest author we know of whose philosophical writing has survived. That is, other people before him might have written philosophical ideas, but we have no record of this. He thought quite differently than Thales did. He proposed that the first cause, the first thing, was more abstract. He used the Greek word “apeiron,” which means something like unlimited, indefinite, or boundless. Anaximander those that the apeiron was eternal and unchanging and that, somehow, it had, within itself, all of the opposites (like hot and cold, wet and dry) and that it gave rise to all things without itself being any specific thing. We think he believed that the apeiron somehow generated the cosmos through a process where the opposites separated out, and then interacted, and then later returned into the apeiron.

Anaximenes, a student of Anaximander, seemed to be interested in something more like Thales’ idea, but Anaximenes suggested that air, not water, was the primary substance. He suggested that air, through processes like condensation, could transform into other elements such as fire, wind, clouds, water, and earth. Anaximenes argued that air, unlike water, was everywhere and that it was essential for life. He thought air was a more plausible fundamental principle than Thales’ water.

Pythagoras seems to have believed that numbers were the fundamental principle of the universe. Pythagoras was quite influential in his time. He and his followers believed that everything in the universe could be understood in terms of numerical relationships and proportions. They discovered that musical harmonies are based on simple numerical ratios, and they discovered other mathematical relationships about the world, and this led them to conclude that numbers and their relationships explained the structure and order of the entire universe.

Heraclitus famously argued that fire and change are central to understanding the universe. He’s famous for the saying, “You cannot step into the same river twice.” By that he meant that the river you step in now will be different from the river you step in later, even if the two are very similar. He thought that everything was like this: constantly flowing and changing. Heraclitus saw fire as a symbol of transformation. He argued that everything is always in a state of flux, and that everything is motivated by constant processes of conflict and resolution.

Parmenides thought Heraclitus was wrong about change. Parmenides believe that change is an illusion. He argued that anything that truly exists must be eternal, indivisible, and unchanging. According to Parmenides, the world that we see and experience is a world of change and difference. He thought this was a kind of deception, and that we needed reason to lead us to the truth. That is, the senses experience an illusory world, but the mind can reason its way to the truth about an unchanging, unified reality.

Zeno, a student of Parmenides, is best known for his paradoxes, which he offered to lend support to Parmenides’ views that change and motion are illusory and to critique Pythagoras’ ideas that reality was fundamentally understood through numbers. Zeno’s paradoxes, such as the famous race between Achilles and the Tortoise, seem, at first, to show that motion is impossible. But in fact, the paradox was used to show that motion would be impossible if the universe really was made up of numbers, like Pythagoras suggested. The argument went something like this. Achilles, the fastest runner in the world, is racing against Tortoise, known to be very slow. To make things fair, Achilles agrees to give Tortoise a big head start. Tortoise starts just past the half-way mark between the starting line and the end. Everyone knows that Achilles will easily pass Tortoise and win the race. But Zeno points out that before Achilles can get to Tortoise, Achilles will have to get to the point halfway between them. And, before he can get to the halfway point, he has to get to the point that’s halfway between the starting line and that halfway point. And, since we can divide sections infinitely, there are infinitely many such halfway points. Since there are infinitely many, Achilles will never catch Tortoise, and so will never pass Tortoise, and so Tortoise will win the race. Obviously, that’s wrong, and Zeno’s point was that distances cannot, in fact, be divided infinitely many times, like numbers can. So, the Pythagorean idea, that everything is based on or made of numbers, can’t work, because numbers can be divided infinitely many times, but space cannot be.

Plato’s Metaphysics

Plato, an ancient Greek philosopher, believed that the world we see and experience with our senses doesn’t accurately represent the truth about reality. In fact, he thought there was a deeper, more real world beyond or behind the world that we can see or touch. Plato called this deeper reality the world of “Forms” or “Ideas.” He believed that for everything in our physical world, there was a perfect, unchanging version of it in this world of Forms. For example, there might be many different chairs in our world, but in the world of Forms, there’s one perfect “chair-ness” and all of the real, physical chairs have some part of this form. According to Plato, all the things we experience in the world of our everyday life are imperfect copies of these perfect Forms. This way of thinking about reality – with a perfect, unchanging world of ideas being the real one that is behind or that gives rise to the physical world we experience – is a key part of Plato’s metaphysics. Plato’s ideas have been merged with some Christian ideas, and influential Catholic authors like Augustine and Aquinas have provided a worldview that incorporates both the metaphysics of Plato and the dogma and theology of Christianity.

Aristotle’s Metaphysics

Aristotle, another ancient Greek philosopher and a student of Plato, believed differently about the world. Aristotle believed that the real world is actually the one we see and experience, not some separate world of perfect Forms. He thought that everything in the physical world can be understood in terms of what it is made of (its matter) and what its essence is (its form or purpose). For Aristotle, the form (or purpose, or function) defines what the thing is. For example, two different things might both be made of wood (a table and a chair could have the same matter). But their forms (or purposes, or functions) are very different: what the chair is for, the purpose that is serves, is its form, and the form of the table is very different. And, for Aristotle, these things in the world are the real things; and this world is a world of change. There is no separate, perfect, other world where “chair-ness” exists and gives rise to all the imperfect chairs in this world. Aristotle does have his own ideas about unchanging things that are different from Plato’s ideas, and you could learn about those in another course.

Metaphysics between Aristotle and the End of Philosophy’s Ancient Era

For about a thousand years, from just after Aristotle until about the year 600, philosophy in the Western tradition was dominated by Rome. First by Rome replacing Greece as the political center of Europe, then by its embracing of Catholicism, and then by its own collapse. Throughout this time, philosophers continued to explore the nature of reality and metaphysics continued to grow and change. Most of the ideas in metaphysics in this period were shaped by Plato’s or Aristotle’s own works, and of these, especially after Augustine around the year 400, new ideas about Plato were being combined with Catholic ideas into metaphysical assumptions that shaped Western philosophy for more than a thousand years.

Plotinus, in the middle 200s, developed something that today we call Neoplatonism, which is mostly a sort of new interpretation of Plato’s ideas. Plotinus thought that everything that exists comes from a single source, which he called “the One.” This thing, whatever it is, isn’t like the other things that come from it. Unlike the things we experience in the world, all of which have categories of being, the One has no categories. These categories might make sense as levels of reality. So, for instance, you might believe that living things are a higher category than non-living things, and that spiritual things are a higher category than material things. Plotinus, like other philosophers who thought about metaphysics, wondered about these categories of being. He thought that the One was a sort of uncategorizable thing, similar in some respects to Anaximander’s apeiron. Those two ideas share many similarities (they’re both thought of as the source of other things, they’re both thought of as somehow being beyond the traditional categories of other beings, and they’re both seen as unchanging and eternal). However, for Anaximander, the apeiron was an attempt to account for the world without appealing to any kind of mythological or religious system and for Plotinus that doesn’t seem to be the case. The Neoplatonic perspective is heavily influenced by spiritual or religious overtones.

One of the people strongly influenced by Neoplatonic ideas was Augustine of Hippo (who today is recognized by Catholics as St. Augustine). Augustine’s contributions to both Christianity and philosophy were so profound that it’s approximately correct to say that most of both were dominated by his ideas for at least the next 800 years (and in many respects, his ideas as still either dominant or influential).

Augustine’s Metaphysics

Augustine, who lived from about 354 to 430, developed a metaphysical worldview that combined Plato’s ideas, Neoplatonist ideas and Christian doctrine. Within Catholicism, he was probably the most important human contributor to the religion between the disciplines of the New Testament and Thomas Aquinas. He believed, like Plato and some Neoplatonists, that the physical world we live in is not the ultimate reality; but, unlike Plato, Augustine argued that the physical world wasn’t merely a reflection of a more perfect world of Forms but was a creation of God. According to Augustine, God is the highest and most perfect being, and everything else exists because God created it.

He altered Plato’s idea of the Forms. He agreed that there were perfect and unchanging truths, but he thought that they were this way because they existed in the mind of God. For instance, concepts like “goodness” and “truth” are perfect and they are eternal in God’s mind, and the goodness and truth we experience in the world are just reflections of this divine goodness.

Augustine believed in the existence of souls, which he understood to be the true essence of a person. The soul is immortal and seeks to return to God, its source; this is similar in many ways to the Neoplatonic idea of everything coming from and returning to the One. Rather famously, Augustine sometimes argued that evil isn’t a real thing on its own, rather, it is the absence of good.

Like Aristotle, who argued that there had to have been an unmoved mover to start the motion of beings in the universe, Augustine believed that God was that first being. It wasn’t just that all goodness and all truth came from God, on this account, it’s that all of space and time and being did too.

Aquinas’s Metaphysics

From the fall of the Roman empire (476) until about the time of the Magna Carta (1215), Augustine’s views, or views very much like his, dominated the European, Western Asian, and Northern African world. Though Rome had fallen, the Catholic Church still remained powerful and influential. The Platonic and Neoplatonic metaphysical worldview, heavily influenced by Catholic doctrine, was the dominant perspective. Most people believed that the world was created by God, that all the beings in it occupied some place in a natural hierarchy from the lowest forms at the bottom to the highest forms at the top, and that ethics and reason were similarly part of this world and hierarchy. That is, there is a way that “things are supposed to be” that was understood to be parallel to “the way things are.”

Thomas Aquinas, who lived during the 1200s, added to this worldview by reintroducing Aristotle’s ideas to the Western world (Aristotle’s ideas had been preserved in Arabic and Persian libraries). After Aquinas, the Protestant Reformation, the Renaissance, and the Scientific Revolution all followed within a few hundred years. It is not unreasonable to conclude that the reintroduction of Aristotle’s ideas was partly responsible for all of these changes.