Plato’s Metaphysics

Doctrine of Separationism (or Two Realms)

• Changing world of particular things characterized by identity and

difference•World of unchanging, immaterial,

and eternal Forms.

Realm of the Forms - Intelligibles

Different Substances

SameAttributes

Realm of the Physical World - Sensibles

Identity in Difference

TALL

FRUIT FRUIT

TALLNESS

TALL

Bill LindaRover Dax Apple Banana

How do we explain real identity in real difference?

WHITE & BROWN

WHITE & BROWN

NYLON

NYLON

NYLONNESS

WHITENESS/BROWNNESS

FRUITNESS

Realm of the Forms

Beautiful Beautiful

Angelina Jolie Helen of TroyDifferent Persons

SameAttribute

Identity in Difference

Realm of the Physical World

BEAUTY

The FormsHypothetical entities designed to explain how numerically or

quantitatively distinct things can be qualitatively identical.

The Basic Argument

1. If identity in difference exists, then the Forms exist.

2. Identity in difference exists.

So, 3. the Forms exist.

Beauty (f1) in Angelina and beauty (f2) in Helen are the same, but Angelina (A) and Helen (H) are not the same.

Two numerically distinct things can only have identical properties if there are higher entities

that make this possible.

A is f1 H is f2

F

• F must be distinct from f1 and f2, otherwise F could not be the same thing in f1 and f2.

• F must be identical with f1 and f2, otherwise there is no basis for saying that A and H have the same attribute.

The Forms are universal entities so other things can participate in their

existence.

The Forms are also concrete, for they are substances or things,

though distinct from physical things.

Individual physical things participate in the forms by having

the natures of the forms.