Maybe Origin holds up better than I would guess but honestly, I'm never going to read that thing. You've got time to read a few thousand books in your life. And I would bet there are many modern books which cover the same material with a more accessible bent and more up to date and comprehensive information.
I'm not saying this as some kind of philistine. I studied literature for several years at university. I enjoy it. I've read Dante, Ovid, Thucidydes, Chaucer, Kant, and many more. But most those books are really interesting in historical or pedagogical kind of way. They show you the development of writing as it progressed. And they demonstrate the changing of human philosophy and epistemology. But frankly, most modern people can derive the same concepts and style as they've been handed down and filtered through subsequent authors.
Despite the hullabaloo about people declining to read, we live in an amazing literary time. Really good books are being written right now on just about every subject. The writing world is so competitive that authors really have to hone their skill. Especially in the non-fiction category which for several decades has been under a deluge of well researched, focused and didactic books.