The Fountainhead was by Ayn Rand in 1943 (with a movie I haven't seen yet), who is also notable for 1957's Atlas Shrugged, both fiction among others in non-fiction.

https://en.wikipedia.org/wiki/The_Fountainhead
https://en.wikipedia.org/wiki/The_Fountainhead_(film)
The Fountainhead (1949) - IMDb 7.1/10

https://en.wikipedia.org/wiki/Ayn_Rand

https://en.wikipedia.org/wiki/Atlas_Shrugged
https://en.wikipedia.org/wiki/Atlas_Shrugged_(film_series)
Atlas Shrugged: Part I (2011) - IMDb 5.6/10
Atlas Shrugged II: The Strike (2012) - IMDb 5.4/10
Atlas Shrugged: Who Is John Galt? (2014) - IMDb 4.3/10

Nietzsche wrote a bunch of other stuff too, but I don't know them to recommend them other than maybe Will To Power.
https://en.wikipedia.org/wiki/Thus_Spoke_Zarathustra
https://en.wikipedia.org/wiki/Friedrich_Nietzsche

 

You didn't get very specific.

It really depends what kind of philosophy you like with your novel - how deep, and what for, or what freedoms you seek. All these have very deep and quirky ideas about all sorts of stuff - and there are so many in between. Depends how much story you want and how much philosophy - or how much you like drugs and innerspace or on the road shamanism or sci-fi and outerspace or something formal.

https://en.wikipedia.org/wiki/Franz_Kafka
https://en.wikipedia.org/wiki/Jean-Paul_Sartre
https://en.wikipedia.org/wiki/Henry_Miller
https://en.wikipedia.org/wiki/Jack_Kerouac
https://en.wikipedia.org/wiki/Richard_Brautigan
https://en.wikipedia.org/wiki/Italo_Calvino
https://en.wikipedia.org/wiki/Robert_Anton_Wilson
https://en.wikipedia.org/wiki/Tom_Robbins
https://en.wikipedia.org/wiki/Douglas_Coupland
https://en.wikipedia.org/wiki/Neal_Stephenson

https://en.wikipedia.org/wiki/A_Confederacy_of_Dunces
https://en.wikipedia.org/wiki/A_People's_History_of_the_United_States
https://en.wikipedia.org/wiki/Acid_Dreams_(book)
https://en.wikipedia.org/wiki/Bardo_Thodol aka The Tibetan Book of the Dead
https://en.wikipedia.org/wiki/Brave_New_World
https://en.wikipedia.org/wiki/Contact_(novel) by Carl Sagan
https://en.wikipedia.org/wiki/Cyrano_de_Bergerac_(play)
https://en.wikipedia.org/wiki/Dune_(novel) and sequels by Frank Herbert
https://en.wikipedia.org/wiki/Fahrenheit_451
https://en.wikipedia.org/wiki/Gödel,_Escher,_Bach
https://en.wikipedia.org/wiki/Infinite_Jest
https://en.wikipedia.org/wiki/Jonathan_Livingston_Seagull
https://en.wikipedia.org/wiki/Neo-American_Church Boo Hoo Bible (I have one, very rare, bought from Winona Ryder's dad, Michael Horowitz, Timothy Leary's archivist.)
https://en.wikipedia.org/wiki/Stray_Toasters graphic novel
https://en.wikipedia.org/wiki/Tao_Te_Ching
https://en.wikipedia.org/wiki/The_Art_of_War
https://en.wikipedia.org/wiki/The_Dancing_Wu_Li_Masters
https://en.wikipedia.org/wiki/The_Electric_Kool-Aid_Acid_Test
https://en.wikipedia.org/wiki/The_Hitchhiker's_Guide_to_the_Galaxy
https://en.wikipedia.org/wiki/The_Paper_Bag_Princess
https://en.wikipedia.org/wiki/The_Psychedelic_Experience
https://en.wikipedia.org/wiki/The_Songs_of_Distant_Earth
https://en.wikipedia.org/wiki/The_Tao_of_Pooh
https://en.wikipedia.org/wiki/The_Teachings_of_Don_Juan
https://en.wikipedia.org/wiki/Walden
https://en.wikipedia.org/wiki/Zen_and_the_Art_of_Motorcycle_Maintenance

I haven't read but maybe:
https://en.wikipedia.org/wiki/The_Prince by Niccolò Machiavelli

Among my faves, I suspect you can't go wrong with these:
https://en.wikipedia.org/wiki/Steppenwolf_(novel) and
https://en.wikipedia.org/wiki/Siddhartha_(novel) by
https://en.wikipedia.org/wiki/Hermann_Hesse