So I just got a few works by Sartre(Being and Nothingness, Nausea and Transcendence of Ego), Nietzsche(Beyond Good and Evil), Descartes(meditations), and Plato(The Republic). But I have to admit that I'm having struggling to comprehend what they're saying.
I have some trouble getting (1) they're ideas,(2)the constant reference of other Philosophers, and (3)why they think that way. So I feel like I there are prerequisites before I start reading any of these.
I have read some Albert Camus and was able to grasp his ideas, but I what I've read from him were novels. I want to read they're non-fiction works. Any advice?