and what is presented in the image as the sun, fire, and light? What does light mean? What is the connection between idea and light?
Ἰδέα (ἰδεῖν, to see) = what is seen, what is perceived in seeing. Now, what does “seeing” mean here? Seeing as perceiving with the help of the eyes. We see the book, so we say. But if we look more precisely at what we actually see with the eyes, distinguishing it from what we hear from the ears, we reach the conclusion that with the eyes, we see things such as color, brightness, and something shiny.
But we also say: we see that something is moving. But we hear this too. For example, we hear that a car is getting closer or farther away. But the perception of things in motion is not restricted to the senses of hearing and seeing. I can also feel it. The proper domain for visual perception is color, brightness, clarity. So we really cannot say: we see the book. And the dog does not “see” the book either, nor can it ever see it; it sees something colored.
If we now say, despite all this, that we see the book, then we are using a concept that is broader than seeing as sensory perception. This broader concept becomes definitive for ἰδεῖν and ἰδέα. So, in the strict sense, I cannot see the book.
b) The seeing of what‑Being. Idea and Being:
presencing—self‑presence in the view
But we can say: I see in this given, tangible, audible, visible, graspable thing that it is a book. I see this in it. What is given offers me insight, a look at a book. So that as which something offers itself (as chalk, as book, as lamp) is that within which the relevant thing presents itself, that is, exhibits its self-presence.
The Greeks call the presentness of a thing Presence. Presentness is equivalent to Being for them. οὐσία = presence, that as which a thing is presencing; that which is its essence, or in short, its Being; that as which a thing offers itself, what a thing looks like = εἶδος. ἰδέα is just another form of the word εἶδος. ἰδεῖν: the seeing of a thing. ἰδέα: the appearance, the look that it offers; that in which something shows itself as it is; what something looks like, the appearance of something.
For the Greeks, the idea is nothing other than Being, what something is: the Being that pertains to it.
If we look more closely, supposing that our comprehension were limited to the realm of what the things give us—color, brightness, and the like—if we had only all these as givens, then we would have no world at all.
I can identify this thing in front of me as a book only insofar as I know and understand in advance what a book is. If we did not have the understanding, the possibility of seeing this book as a book could never come up. But instead there is a distinctive advance knowledge of things on