I've started reading Nehamas' 'Only a Promise of Happiness', which reminded me that I've been focusing on the Kantian curiosity-porn aspect of responding to art/nature, to the exclusion of other philosophically interesting things that looking at things which are standardly called beautiful does for us.
So I propose that what people get from the 'great' novels and natural beauties they appreciate typically includes at least three things
1. epistemic pleasure: the fun of discovering lots of striking and salient things new things, not by luck and effort but just by considering the beautiful object in ways that it seems to objectively invite. [i.e. the curiosity porn aspect]
2. direct pleasure [e.g. the pleasure that people who like to color purple get from looking at it, according to Kant, and maybe the pleasure of tasting sugar.]
3. project-based pleasure: the pleasure of discovering new projects, which we are disposed to care about non-instrumentally.
Now I want to say some things about why I include this third ingredient.
a. We DO seem care about lots of things non-instrumentally. For example:
You're sharpening a pencil to write a poem, but why are you writing a poem?
You're taking the asprin to end your pain, but why are you trying to ending your pain?
You're buying the wine to impress this person, but why are you trying to impress this person?
You're doing this grading so you can have the opportunity to think about philosophy, but why do you want to think about philosophy?
You're moving that card so you can win the solitaire game, but why do you want to win the solitare game?
b. Given sufficient leisure, we typically want to discover MORE such things that we can care about for their own sake.
Not having any desires or plans which you can act to further, feels boring and frustrating - one might even say depressing. And conversely, things like games which are designed to give people pleasure do so largely by making us desire new things, so that we can then have the pleasurable experience of making progress towards them.
Sometimes (in a gloomy mood, or e.g. at the end of a romantic relationship when you have to give up on lots of large scale projects, and things you care about all at once) it can be a real challenge to find things to care about in the world around you. I like to think about people picturesquely as projecting themselves forward into planed future situations, and then -as they pleasurably drag forward, making these plans actual- projecting further forward to that to make new plans, like an earthworm that thrusts its front parts into the earth and then drags its hindparts along, then thrusts its front parts forward again. (Unlike earthworms though, humans would have many alternative possible plans they are pushing towards.) [Hmm...this whole conceit may be a result of misunderstanding the one heidigger class I took in college] Anyways, it hurts when your delicate front plan-making parts get cut off, i.e. there stops being a practically viable path from where you are, to the stuff that you want and care about. And it's boring and frustrating when you don't have any plans you care about to push forward into.
So, you will generally want to "diversify your portfolio" of plans, and hence like discovering new plans that appeal to you, plans which you could come to care about more.
c. Art/nature which we like, very often helps us find more stuff that we can care about (either by bringing new possibilities to our attention or by describing old ones in a vivid or unusual way)
the most trivial examples of this kind of effect of beauty would be:
-wanting to follow a winding path in a beautiful landscape
-wanting a character to do well in a story (here the possible plans are rather limited to monitering their situations and hoping for the best, though)
-some character in a story acts in a distinctive way, which you think is cool and want to emulate