1. Allegory of the Cave Theory of Forms
Metaphysics
Allegory of the Cave
Theory of Forms

2. Plato and Aristotle
Which is which? What are they doing with their hands? Where are they? See the full painting here

3. The Great Three Plato (429 - 347) Socrates (469 - 399)
Greek Philosophers (500BC – 200BC) Timeline
The Great Three
Plato, 20, meets Socrates, 60
Aristotle, 17, meets Plato, 62
Plato ( )
500 BC
200 BC
Socrates ( )
Aristotle ( )

4. Allegory of the Cave (Analogy of the Cave)
What is an allegory?
It’s a story that teaches you about something other than what is in the story.
What is an analogy?
A comparison made to show a similarity.

5. Resources
Watch this YouTube video of the Cave Allegory Read this excerpt from Plato’s Republic, Book VII, if you prefer reading to watching

6. Purposes of the Allegory
Plato’s Cave Allegory has a number of purposes:
distinguish appearance from reality
it is possible to have the wrong understanding of the things we see, hear, feel, etc.
explain enlightenment
moving from ‘shadows’ to ‘the real’
involves pain, confusion
makes you an outcast
is a one-way trip
improves you, but
makes you a nerd
makes you mentally clumsy
cannot be taught, you must see for yourself

7. Purposes of the Allegory (cont.)
Plato’s Cave Allegory has a number of purposes:
distinguish appearance from reality
explain enlightenment
introduce the Theory of Forms (or Ideas)
the allegory provides for an analogy:
as shadows are to physical things, physical things are to the Forms (Ideas)

8. Platonic Forms (Ideas)
In virtue of what are these two things red? It’s not the paint, dye, pigment, light waves, frequency of waves, etc., that makes the circle on the left red, that makes the circle on the right red, because all that stuff is over there (on the left) rather than over here (on the right) … similarly, it’s not the paint, dye, pigment, light waves, frequency of waves, etc., that makes the circle on the right red, that makes the circle on the left red, because all that stuff is over here (on the right), rather than over there (on the left). So, in virtue of what are they both red? Notice that ‘red’ is a singular term … the subject is plural, but the predicate is singular! These are not ‘reds’. How can this be?! How then, can two things be one thing?!

9. Platonic Forms
In virtue of what are these two things circular? It’s not the curve of the border that makes the circle on the left circular that makes the circle on the right circular, because that curve of the border is over there (on the left) rather than over here (on the right) … similarly, it’s not the curve of the border that makes the circle on the right circular that makes the circle on the left circular because that curve of the border is over here (on the right), rather than over there (on the left). So, in virtue of what are they both circular? Notice that ‘circular’ is a singular term … these are not ‘circulars’! How then, can two things be one thing?!

10. Platonic Forms
Consider: The 3 angles of any triangle add up to two right angles This is a feature not just of each triangle, but, for Plato, of triangularity. Triangularity, because of that universal trait (a trait had by all triangles), came to be called a Universal.

11. Platonic Forms (Ideas)
Plato thinks we need universals to account for our knowledge. If, as Heraclitus said, the only thing real is flux or change, then we couldn’t know anything (nothing our thoughts were about would match our thoughts, since what underlies our thoughts is always changing).
Consider the statement:
blue is darker than yellow
What would happen if every blue and yellow thing winked out of existence? Would the statement be false?
Similarly, when we know
The 3 angles of any triangle add up to two right angles
there must be something outside of the physical world that makes that statement true, since nothing in the physical world could.

12. Platonic Forms (Ideas)
Plato believed that these Forms, or Universals, are:
Eternal
Unchanging
Necessary (exist [subsist?] necessarily)
If they were not so, ‘blue is darker than yellow’ and the truths about geometry, and innumerable others, could all be false. But, when you think hard about them, they apparently cannot be false.