I read his magnum opus in college: The World as Will and Representation (in german, Die Welt als Wille und Vorstellung). It's quite long and dense, but essenti

I read his magnum opus in college: The World as Will and Representation (in german, Die Welt als Wille und Vorstellung). It's quite long and dense, but essentially presents a kind of dualistic philosophy that doesn't necessarily need any kind of supernatural mechanisms. I don't necessarily subscribe to his beliefs or world view, but I found them quite interesting. I particularly enjoyed the later stages of the book that discussed pessimism, suicide, why suicide is not the correct answer to pretty much any problem, and other such "dark" themes. Anyone can write the "happy path" of philosophy, so to speak, but Schopenhauer clearly trod a more melancholy path.