Looking for a work that deals with the topic "ideal"

Hi. I hope this is the right place to ask.

I am looking for literature where I can find something on the idea of "ideals". Ideal as in, the things one might hope to achieve or obtain as opposed to reality.

I know I'm being a bit vague, I just need some literature I can work with for a school project on the topic of "reality and ideal" in book xy.

If anyone has any ideas I would be gratefu

Looking for a work that deals with the topic "ideal"