1. Allegory of the Cave Theory of Forms Plato, Aristotle, Ockham
Metaphysics
Allegory of the Cave
Theory of Forms
Plato, Aristotle, Ockham

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.

13. Platonic Forms (Ideas)
Qualities
colors
shapes
sounds
textures
temps
flavors
odors
aspects of all
etc.
Relations
lighter/dark er
rounder/squ arer
higher/lower
rougher/smo other
sweeter/sour er
etc.
Kinds
animal
vertebrate
human
metal
steel
apple
book
sandwich
etc.

14. Platonic Forms (Ideas)
Where are these Forms?
Because everything in space and time
comes into being at some time and in some place, and
goes out of being at some time and in some place,
the Forms, eternal and unchanging, must be outside space and time.
Some call this place Plato’s Heaven
Some call the Forms Divine Ideas

15. Platonic Forms (Ideas)
Problem:
How do Plato’s non-temporal, non-spatial, eternal, unchanging Forms interact with the temporal, spatial, temporary, changing world of our experience?
Plato tells us: by a relation of ‘participation’ or ‘sharing’
Another way to say it, Forms are ‘instantiated’ in physical things.
This red thing has an instance of redness,
this ‘being in between’ is an instance of inbetweeness,
this dog is an instance of dogness.
But, how do physical things participate in Forms? Or, how are the Forms instantiated in things?

16. Aristotle’s Universals
Aristotle rejected Plato’s Forms as entities that exist separate from the things that instantiate them.
He held, instead, that the Forms exist only
in re (in things), and not
ante rem (before things)
and, that we know them by lifting them out of sensible objects by abstraction
simple (just noticing a feature of something)
common (recognizing two features are one and the same)
precise (cutting off reference to all other features)
It is the last kind of abstraction Aristotle believes Plato uses, illicitly, to derive his concept of separated Forms

17. Aristotle’s Universals
There are Forms only for those qualities, relations, and kinds that
have existed,
exist, or
will exist
What it means to be a universal is to be ‘predicated of many’.
His emphasis on language led medieval commentators to follow suit, and seemingly led to both
Conceptualism (universals are concepts in the mind), and,
Nominalism (universals are a mere ‘puff of voice’; universal words)

18. Ockham on Universals
William of Ockham (of Oak Hamlet, Surry, England) rejects both Plato’s and Aristotle’s views about Universals.
Ockham is a Nominalist (some scholars now think he should be considered a Conceptualist instead).
From Paul Spade’s Stanford article on Ockham:
He [Ockham] believed in “abstractions” such as whiteness and humanity, for instance, although he did not believe they were universals. (On the contrary, there are at least as many distinct whitenesses as there are white things.) He certainly believed in immaterial entities such as God and angels. He did not believe in mathematical (“quantitative”) entities of any kind.

19. Ockham on Universals
Ockham, from the Internet Encyclopedia of Philosophy:
There is no universal outside the mind really existing in individual substances or in the essences of things…. The reason is that everything that is not many things is necessarily one thing in number and consequently a singular thing. [Opera Philosophica II, pp ]

20. Ockham on Universals
Ockham provides an argument to support his view … from the Internet Encyclopedia of Philosophy, again:
…it would follow that God would not be able to annihilate one individual substance without destroying the other individuals of the same kind. For, if he were to annihilate one individual, he would destroy the whole that is essentially that individual and, consequently, he would destroy the universal that is in it and in others of the same essence. Other things of the same essence would not remain, for they could not continue to exist without the universal that constitutes a part of them. [Opera Philosophica I, p. 51]
Does this argument work equally well against both Plato’s and Aristotle’s conceptions of universals?

21. Resemblance Nominalism
If Ockham’s view is best characterized as ‘Resemblance Nominalism’, or ‘Resemblance Conceptualism’, what arguments weigh against it? Read Rodriguez-Pereyra, if interested. (You are not responsible for anything from this link)

22. References
Socrates’ image:
Plato’s and Aristotle’s images: