What Is Plato’s Theory of Forms?

Plato’s Theory of Forms was the foundational work that paved the way for many of his future philosophical ideas. We provide a brief overview.

Aug 6, 2023By Luke Dunne, BA Philosophy & Theology

what is plato theory of forms


  • Plato’s Theory of Forms is a foundational metaphysical concept suggesting that true reality is comprised of abstract, ideal entities (Forms) which differ from how things appear.
  • Plato’s cave analogy is a famous depiction of his Theory of Forms: people initially see mere shadows (appearances) but eventually can perceive real objects illuminated by the sun (true Forms).
  • Despite controversies, this theory remains a pivotal contribution to Western philosophy, underpinning many of Plato’s subsequent ideas.


Plato’s influence on Western philosophy (and culture in general) has been profound. One of the central ideas in Plato’s work is his Theory of Forms. The Theory of the Forms is what is known as a metaphysical theory. Metaphysics, in a broad sense, refers to theories about how reality is fundamentally or in general. It is one of the most abstract branches of philosophy. For Plato, his Theory of the Forms is the foundation for most of his subsequent philosophical work.


Theory of Forms is Plato’s Most Important Metaphysical Theory

A panoramic view of Athens, via Ekathimerini


Plato was one of the two most important philosophers of Ancient Greece, along with Aristotle. He lived in Athens during the 5th century BCE. Between Plato, Aristotle and some of the earlier philosophers (so-called Pre-Socratic philosophers) like Parmenides and Heraclitus, the Greeks developed philosophy in a form which is still recognizable to philosophers today. 


Plato was the student of Socrates, and much of Plato’s work takes the form of dialogues between Socrates and a wide range of conversation partners. Socrates was probably a real man, but it is very hard to distinguish how much of Plato’s work is original, or reporting the beliefs of his mentor (as it purports to be).


The Theory of Forms is one of Plato’s most important theories. It is a central assumption of much of his philosophical work, and it is very hard to understand Plato at all without understanding this theory.

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It Explains How Things Really Are

La Table, Pierre Bonnard, 19th century, via The Tate


We’ve already said that Plato’s metaphysical theory is known as the Theory of the Forms. But what are Forms? Don’t forms have to be forms of something else? So, what exactly is this a theory of? Well, to understand this we have to understand that Plato was one of those philosophers – of whom there have been many – who thinks that the way things really are is quite different from the way things appear to be. Indeed, the distinction between appearance and reality is arguably the core Platonic distinction. 


For Plato, the Forms of what is really real, and they are the Form of certain things that appear to us. If that sounds complicated, consider this analogy. Imagine you are looking at a table.It has various qualities that are particular to that table: it’s made of mahogany, it has thin legs, it is placed near to a window (and so on).


 But there might be certain qualities which qualify it to be a table – in other words, certain qualities which explain how and why it is similar to other things we call tables. For Plato, the idea of a table is something we might be able to abstract from various individual tables, and that abstraction would be the Form of the table. Forms are these abstract, ideal entities. We cannot perceive them directly


It Is a Complicated Theory

Since I Have Left You Mine Eye is in My Mind, Keith Michell, 1976, via Tate


Plato makes a great number of arguments in favour of his Theory of the Forms, and there isn’t enough space to cover all of these arguments here. Indeed, because the Theory of the Forms crops up in a wide range of Plato’s writings there is a lot of scholarly controversy over whether we should speak about Plato as having a Theory of the Forms, several, or none at all.


Moreover, because Plato’s writings take the form of dialogues and therefore leave the reader to decide on the correct interpretation, the Theory of the Forms is thrown into further doubt.


One quite famous ambiguity is over the kind of things which have corresponding forms. At certain points, it seems as though Plato thinks only quite abstract qualities – like goodness, truth or beauty – have corresponding forms. However, at other points it seems like even ordinary objects – like the table in the example above – might have forms as well.



It Explains How We Can Understand the World

Goethe in the Roman Campagne, via Pixabay


Probably the most famous argument Plato makes for the Theory of the Forms comes by way of the following analogy. Plato asks us to imagine that we are in a cave. All around us is darkness. The only think we can see is on the wall before us, where a light is shone and shadow figures dance on the wall. These are being manipulated by unseen tormenters.


For Plato, this is what the world of ordinary appearances is like. Plato then asks us to imagine that we break our bonds and escape out into the open air. We see flowers and trees and everything else clearly, as it really is. The light we see by is no longer the obscure light of the cave but the bright, clear light of the sun. For Plato, this is what the World of the Forms is like.


It is a Major Contribution to Western Thought

Raphael, The School of Athens, 1511, via Musei Vaticani.


In short, Plato’s Theory of the Forms is one of the most important theories in Western philosophy, in spite of controversies over how it should be interpreted. Plato argues for it using the famous cave analogy, and then goes on to use it to underpin many of his subsequent philosophical theories.

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By Luke DunneBA Philosophy & TheologyLuke is a graduate of the University of Oxford's departments of Philosophy and Theology, his main interests include the history of philosophy, the metaphysics of mind, and social theory.