Excerpt from How to Look: Art Comics by Ad Reinhardt
Viewer: ha-ha what does this represent?
Painting: what do you represent?
An abstract painting will react to you if you react to it.
You get from it what you bring to it.
It will meet you halfway but no further.
It is alive if you are.
It represents something and so do you.
You, sir, are a space, too.
Realistic paintings tell you exactly what they are, while abstract paintings invite you to think.
This applies to not only paintings but also other things, such as books and people.