Terms:
Metaphysics: philosophical theory of being or reality.
Plato: being = idea or Form.
Intelligible: things grasped by the intellect
Sensible: sense perceptible
Things grasped by the senses are not ideas but merely appearances of the ideas/Forms themselves.
Example: perfect form of a triangle = idea/form of the triangle.
Any triangle I draw/see in reality = appearance
For Plato these forms are “higher” than material things.
“The Good”: that which makes everything good. The idea of the good is the best thing anyone can know. To attain this Good is the task of wisdom/philosophy. This understanding of the Good would not be opinion ( doxa in Greek), but the Truth.
People who know the Good should be the rulers of government (i.e. Philosopher Kings).
Everyone desires what is good. To know the Good for ourselves is to know the best state of all other things.
Opinions without knowledge are shameful and aweful. Opinion is shameful for Plato because we take it for granted. It only comes (i.e. people form their opinions only) when you take a perception and judge it as true.
You should either know, or know that you don’t know.
Criticism of democracy: Democracy requires opinion, discourse, and so on. The wise are impatient about that. The wise possessing true knowledge have no patience for that sort of thing (i.e. democratic discourse).
Why should life be examined? In order to figure out what is opinion and what is knowledge.
Plato doesn’t say opinions are false but that it comes down to a difference (knowledge) between understanding and passion (opinion).
Analogy for understanding:
Sun: visible things: sight
Good: intelligible things: understanding

Idea of the good: i) Intellect (knowledge/truth): causes intellect to understand ii) ideas (being): causes beings to be
To understand is to focus the intellect or the true ideas.
The criteria of knowledge is infallibility, Opinions lack this.
The object of true knowledge is true being.
The object of opinion mixes being with knowledge and is uncertain.
An allegory of 3 separate levels:
1) The Human situation: We are these slaves tied up in the cave. This world we know through our senses are the shadows. We are addicted to doxa . Prisoners take things in a very naive way.
Example: The Matrix Trilogy, Inception
2) Enlightenment (Philosophical): To discover what philosophy offers. What it offers is a conversion
“from down here to up there” (i.e. from inside the cave out into the sunlight). From senses to knowledge, Socrates though that anyone could be improved by this process.
3) Democracy: Cave represents the democratic city. The slaves are the people. The allegory makes you hate democracies and opinions. The philosopher is regarded a fool by the mere mob. Chains = opinion. They hold us in servitude in a democracy. Way to overcome the disorder of the city/individual is to unite political power with philosophy. (i.e. Plato calls this the philosopher king).