While not as opaque as Heidegger, Sartre presents his own challenges in understanding his evolution of thought and how this supplied the world with a definition (so called....) of existentialism. Bernasconi does a good job of presenting an overview, if only to help me realize that I need a LOT more immersion in Marx, Nietzsche, and Heidegger, pulling in Dewey and Lacan along with some others, in order to get a better handle on where we are today, what brings us here, and maybe a clue to where we're being thrown (H/T to Heidegger.....).