1. Forms and the Good

2. It all comes from the cave
The allegory of the cave is a grand summary of Plato’s key ideas. In it he explains:
the difference between knowledge and opinion (the shadows)
the importance of reasoning rather than empirical knowledge
the true nature of reality
how society should be organised.
You might want to remind yourself of these ideas before we move on.

3. Which of these is a chair?d

4. Which of these is beautiful?

5. Plato argues that we are able to recognise the Form of dog, the chair, or beauty.
In the case of dogs and chairs, we might object that these are names we have learned and that we are merely comparing the new objects to all the other things we have learned to give that name to.
The case of beauty is more difficult: the four beautiful things are all quite different, yet there seems to be something common that they share.
It is worth remembering that the things we see and hear are ultimately just matters of opinion or belief. We know the Forms because they are accessed via our mind.

6. Anything in Particular?
Plato says that the particulars are imperfect copies of the Forms.
The particulars share in, or participate in, the Form.
Some things participate to a greater or lesser extent. Why not try cutting some pictures out of a magazine and arranging them in order of how much they participate in the Form of beauty. You may be surprised to find that your fellow students generally agree with your idea of beauty!

7. The world of the Forms (the Real World)
The world of Particulars (our world/the cave)
Each Form is One (there is only one idea of beauty)
Particulars are many (there are many beautiful things)
Intelligible = only known through our intellect/reason
Sensible = only known through our empirical senses
Eternal
Always coming in and out of existence (birth and death, or made and destroyed)
Unchanging
Always changing into something else
Non-physical
Material objects
Perfect
Imperfect

8. How many Forms?
There are various types of Forms, but broadly speaking everything has a Form.
There are Forms for values like Beauty, Justice and Wisdom.
There are Forms for living things like dogs and frogs, and Forms for objects like tables and chairs (Forms can be thought of as types of things).
There are Forms for mathematical concepts like circles and triangles. Maths is ‘exciting’ to Plato as mathematical truths are necessary and certain. Two plus two isn’t just 4, it has to be 4.

9. A Form of the Forms?
The Form is what all the particulars have in common. So all cats share in the Form of cat-ness.
Some critics of Plato have pointed out that surely Plato needs a Form of the Forms to explain what the Forms have in common and then a Form of the Form of the Forms and so on.
In a way Plato does have a Form of the Forms but he has good reasons for thinking that the chain stops there.

10. The Form of the Good The ultimate Form is the Form of the good.
Remember: the Forms are perfect - their perfection or goodness is something that they share.
Just as the sun in the allegory of the cave gives light to the real world, so the Form of the Good illuminates the other Forms.
It is the reason why the Forms are Good.
It enables us to ‘see’ the Forms.
It is the ultimate end in itself: the aim of everything is goodness.

11. Back to the Cave
So, only the philosopher who escapes the cave and the reliance on their senses can see the sun and know what goodness is.
Hence they are the only ones who are fit to rule society.