When did you learn that a table is a table? Chances are it was when you were but a toddler. A parent no doubt told you that this was a table and that was a table, so your brain processed the information and created a notion of the table.

Or did it? Do we put together pieces of evidence on what something is and then create a concept or is the concept already within us? When we view an object, a person, a concept, are we viewing it as it is or are we seeing the idealized version of it?

The Greek philosopher Plato created the Theory of Forms to answer the question of reality versus concept. In his theory, all humans learn about the eternal, unchanging ideal form of something, be it an object or a concept, prior to being born.

In this article, I will go into more depth about Plato’s Theory of Forms, what it is, how it works, and how it relates to metaphysics and concept formation. I will then create additional articles on the long-term impact of his theory and Aristotle’s rebuttal. 

Part 1: What is the Theory of Forms?

What is Plato’s Theory of Forms?

I’ll try to keep this simple though it’s not that easy. Basically, Plato divided the world into two – the ideal and the real. He put an emphasis on the good of the former over the latter. Let’s look at both:

The Ideal: Every object, function, and idea has an ideal form. This is the best possible and only possible, unchanging, and perfect form.

The Real: An object or being which can be sensed or a notion which is seen in practice. No matter how good it is it will never be as good as the ideal.

There is also the idea of perception and this is important. When someone senses the real object or notion in practice, they do not perceive it as it is, but instead perceive it in relation to the ideal form which is conceived innately within them.

In short the Theory of forms is an abstract contraption designed to explain what is Good and what is True according to Plato. It meshes together perception, knowledge (including epistemology), the soul, and the organization of society.

How do we know what the ideal form is?

It might help to understand where Plato is coming from by understanding how he believes we acquire the knowledge of the forms. In Timaeus [41e] Plato explains how humans come to know what the ideal forms are. I’ll break it down into bullet points to make the flow easier to see:

1. God creates the matter for all souls in one ball.
2. God then divides the ball makes a soul for every star in the sky. These are all the souls that will ever exist.
3. He mounts each soul on a star.
4. Each soul is then inculcated with the nature of the universe (the forms) and the laws of destiny.
5. They are then born at their allotted times and bond with the physical reality of their corporeal bodies.
6. After life, those who know the ideal forms will go back to their star for eternity.
7. Those who fail will degrade into women then to animals via reincarnation.

Therefore Plato is positing that the ideal form exists in a metaphysical world or “Realm of Forms” which is a place where each immortal soul is taught about these ideals. We are then born with these ideals innate within us and if we harmonize with them we do not degrade and go back to the Realm of Forms.

Did Plato invent the theory of forms?

No. It seems that the Theory of Forms had existed in Greek philosophy for quite some time as they morphed from a tribal pagan society into one embracing philosophy, discourse, and debate. Sadly, due to a reliance upon slavery, Greek society never evolved into science and the scientific method.

Anyway, the first known Greek to discuss what something really is – how do we know a chair is a chair and does it always remain a chair? was Thales. His answer to this question was substance.

We then come to eidos, which means ‘seen form’ in Ancient Greek and has its root in Proto-Indo-European and the hypothetical word *weid meaning ‘see.’ This root word gave us view, advice, guide, Druid, penguin, idol, twit, and prudent.

So in short, the idea was being discussed long before Socrates and Plato, but it is Plato who discussed the idea in the most depth.

Part 2 – Examples of the Theory of Forms

I’m going to divide this into two examples. The first will be of a seen object – an axe, and the second will be an unseen concept – beauty. Finally, I’ll show how Plato adapted this theory to his most important work – The Republic.

Theory of Forms: Seen

Let’s take the seen forms first. This is not to say that we see or sense in anyway the Forms that Plato is talking about. What he means is that every physical object comes with an ideal form which is known but unseen. No seen object can compare to the idealized unseen form of that object/function.

As an example, in Timaeus [28a-b], Plato lays out two scenarios, one good and one bad, for a craftsman making an object. Let’s use the example of an axe.

The good scenario: The craftsman would engage with the ideal form and function of an axe, and would then craft the tool from that ideal. This would create a good axe.

The bad scenario: The craftsman looks at existing axes and creates his axe from these existing forms as a kind of copy. This would create a bad axe.

The ideal form of an axe

As an archaeologist I’ve often had problems with the classification of objects along typological lines. It’s an interesting theory – a type of object can be chronologically ordered from the most simple/basic to the most complicated/effective. My problem comes from the assumption of continuous progress whereby there’s no reversion to less effective forms or overlap between different forms.

That being said, archaeological evidence helps disprove Plato’s Theory of Forms in this sense because we know that humans have looked at existing forms and sought to improve on them. Humans had stones which became stone axes, which were then attached to handles, then they were further improved, and eventually turned into metal axes and so on.

We do not know if the notion of the axe came from needing a tool to fulfill a function or a function discovered from an existing tool; especially as axes are multi-functional. But we do know that the function requires a suitable tool and that the axe is made to fulfill the function. 

There is also evidence that those creating this tool have applied innovations, trials, errors, and new technologies to improve the tool so it better fulfills the function. Is the craftsman making the axe based on existing axes and the required function or is the craftsman creating it from an ideal notion of what an axe is? I’d say the former.

Theory of Forms: Unseen

In addition to the ideal forms of seen things there are the ideal forms of unseen notions. These are abstract notions and ideas such as truth, liberty, the state, property, the good, etc.. 

This means that there is a perfect form of every notion. How do we know what this ideal form is? If it cannot be logicked into being or empirically tested in life, then the notion’s ideal form is based on a deep, internal knowledge.

Sounds complicated and hard to understand, right? Think about courage – too little courage is cowardice and too much courage is foolhardiness, so what is the ideal form of courage?

The Symposium and the ideal form of beauty

One example Plato concentrates on to quite a degree is the ideal form of beauty. This is seen in multiple books but especially in The Symposium. So let’s use this as an example as we used axes above.

In The Symposium [210-11] Plato lays out ideas of beauty from a male perspective. It’s worth noting that Plato was gay so his focus was on male beauty and attraction to males. Within his culture there was a focus on the beauty of youth, so to grow old means to grow less attractive in that sense. There was less of an idea of growing together as a married heterosexual couple with kids.

Right, so let’s get to it. He states young men become besotted by the beauty of the body and that this is natural, but as a man grows he understands that the beauty of one body is equal to all other bodies, and that in fact all bodies are identical – this would be the form of the body.

So then beauty turns to other elements of the person. This means turning to mental beauty and the beauty of actions. In turn these also become seen as identical within the ideal forms of mental beauty and of action.

Finally then we come to the ideal of beauty – the beauty of knowledge. To Plato knowledge is harmony with ideal forms. He believed the beauty of knowledge, this harmony with the Theory of Forms, to be endless.

Theory of Forms within the State

Plato’s most famous dialogue is known as The Republic though a more accurate translation would be ‘The State.’ It’s a discussion about the ideal state which he admits cannot exist in the material world but which exists within the Realm of Forms.

If the intelligent souls who do not degrade must live in harmony with the Theory of Forms then they must aspire to the perfect state as set out by Plato (this is for another essay). The state would attempt to reach the ideal forms of each notion such as the Good, the Truth, property, and so on.

This takes us back to the unseen notions discussed above. If a notion has an ideal then it would apply indiscriminately to all people. There would be no relativity. However, if the state is designed for the common good then the notion also follows the common good or the good of the many over the good of the few.

Plato believed that the only people who could administer such a state were the philosophers; especially his ideal philosopher king class. This would prevent the degradation of the state and the degradation of knowledge into opinion. Plato’s theory would turn most people to slaves of the philosopher kings and these kings would be slaves to the ideals of the forms.

There were extreme consequences for anyone who might fall into opinion and away from the ideals – death. It’s somewhat ironic that his solution to the mob/state execution of his idol Socrates, was state-sponsored execution.

Part 3: Theory of Forms as an explanation for universals

Is the Theory of Forms an answer to the problem of universals?

Let’s ask ourselves why Plato spent most of his career trying and failing to prove his Theory of Forms. He was trying to solve one of the great questions in philosophy known as the Problem of Universals.

What is the Problem of Universals? The problem of universals relates to the properties of things (objects) and notions. Do these properties exist and if so, what are they?

As with the Theory of Forms, we have to go back to Thales for the problem of universals. He posited the following universal theory:

All triangles inscribed within a circle are right triangles

This prompts the following questions:

How do we know this is a universal theorem?

What is a right triangle?

Are all right triangles right triangles?

What is a triangle?

What is a circle?

We could break that down into every single word within the sentence, but let’s not go that far. So our universals are that:

All triangles have three sides and three angles

All right triangles have a 90 degree angle

All circles are perfectly round

If you fit a right triangle anywhere within a circle so that it’s three angles touch the circle it will form a right triangle.

So we have applied some logic and defined our terms, but how do we know they are all universals? This comes to the age old question which divides Plato from Aristotle. Does the concept inform what we see or does what we see inform the concept?

But we can also go further – even if we can see infinite triangles inscribed within circles and that they are all right triangles, does it make it universal?

Building on Thales’ theory, Plato came to the conclusion that there must be a universal property for each property, and he called this form (eidos). Therefore, all forms we see in the world have an ideal within his Realm of Forms even if we think we’re inventing something new. 

Not only that, but to be a universal form it has to be unchanging and eternal. As we’ve mentioned before, this means physical reality cannot attain to the perfect, so must either be as close as possible or be a degeneration.

My thoughts: There are universal properties. That is to say once something exists as an idea it will always exist even if it’s never known about. The question is how is it provable that a universal property is indeed universal and unchanging or in fact a sound property. Plato’s explanation is not empirical or testable, but is a kind of faith-based answer.

How does the Theory of Forms relate to concept formation?

A key element to universals is the idea of concept formation. Right back at the beginning of this article I used the example of a toddler learning what a table is. How does the toddler end up with the table concept?

The Platonic Theory of Forms dictates that the child came with the theory pre-programmed. Seeing the table unlocked that ideal form within the child’s mind and allowed it to perceive the ideal form or universal of the table.

This means, according to Plato, the universal idea of a table existed before humans had table approximations. In theory that means a prehistoric human hunter-gatherer in the savannah had the ideal form of the table within their mind even though there were no tables. It’s possible they used something natural as a table.

Plato therefore removes concept formation from the human brain and unites a universal concept which can exist beyond humanity with the human soul. It’s not a great fit but is a kind of attempt to understand the difference between universal theories and how we humans come to understand them.

My thoughts: Here Plato is destroying the idea of concept formation within human beings. We’re not able to take in sense data and come to our own conclusions. This removes autonomy and freedom of thought. Instead, he replaces it with concept discovery or perhaps concept revelation.

How does the Theory of Forms relate to epistemology?

The notion of epistemology was not used by Plato directly, so we have to look deeper within his works to try to understand his theories of knowledge acquisition. Most of our knowledge of his theories come from the Theaetetus.

Plato considers three different ideas of knowledge acquisition:

1. Knowledge is perception
2. Knowledge is true judgement
3. Knowledge is true judgement with an explanation why (account)

In Theaetetus he argues against all three without coming to a definitive conclusion. All he achieves in this dialogue is an attempt to crack the certainty of those who believe in the senses.

However, just by its existence as an overarching idea within his understanding and presentation of the world, we can easily argue that the Theory of Forms is a key concept within his notion of knowledge acquisition.

My thoughts: Plato associates knowledge with a deep, unchanging and immaterial feeling or understanding of the world, of forms, and of ideas/notions. He relies on a pure and unchanging truth which is not subject to sense data or empirical study.

Intelligence vs. opinion

Plato also applied his Theory of Forms to his theories of human intelligence. In Timaeus [51c-e], Plato lays out the difference between intelligence and opinion in his mind, and how these fit within his theory of forms.

Intelligence: Perceiving forms having been taught them in the Realm of Forms.

Opinion: Sensing physical reality.

Plato saw opinion as a kind of persuasion. So empirical data on what something is and how it functions whether its a physical object or a notion, persuades a person to change their opinion on what that notion or object is and how it functions.

For him, the certainty of knowledge as taught within the Realm of Forms is a true sign of intelligence. He therefore takes the idea of intelligence beyond the physical world and into the metaphysical world.

He is clear that only a few people are able to separate themselves from opinion to live in a world of intelligence. No doubt (as we’ll see next) these were the philosophers. I would posit that these are more like priests than philosophers.

Conclusion – What evidence is there for the existence of Forms?

There is no known evidence of the existence of Forms. In fact, during his long life and career, and throughout his dialogues, he’s unable to prove their existence except to state that they exist. Such a statement is an article of faith, let’s see why.

The only way to prove the existence of the realm of forms is for the forms to come to Earth and be visible to the senses. Therefore to become material. However, according to Plato’s theory of the forms, as soon as something becomes visible to the senses it is no longer or never has been part of the realm of forms.

If something cannot be material then it must therefore be immaterial. This separates the Forms from empiricism and proof which require logic and evidence. Evidence requires sense data – the material. As the immaterial is impossible to prove or disprove it becomes an article of faith.

This is why some philosophers, such as Stefan Molyneux, put Plato within the realm of theology rather than philosophy. I would agree with this because it reminds me of Martin Luther’s idea on proving God – sola fide – by faith alone.

In short, Plato’s theory of forms is a bad solution to the problem of how we definite properties including universal properties, how we form concepts, and how our brains process ideas and sense data. His explanation relies on mysticism and faith. These are not sound, philosophical bases for an idea.