Earlier quoted context omitted.
Whenever I pick up a maths book, I read all these symbols that have no explanation whatsoever - it's obviously self-indulgent wanking. I admit I don't actually read the book, though, I just open it. But I can tell the symbols aren't english, or any other language I learned before my mind closed, so I can tell it's dross.
Well name a philosophy book that is worth reading. Maths books don't claim to be anything but self-indulgent.
Generally speaking, people who were lucky enough to be born later in time have the advantage over people born earlier, since they can learn from those who come before. This isn't something you have to remember when looking at science since science in the news is if anything too focused on speculation or the latest result over what has been well confirmed - but philosophy has the opposite problem. People still talk about philosophers with ancient names, heavy with dignity even though their ideas have been challenged or extended since their time.
Really, nobody talking about truth should be failing to make a distinction between what is true and what is know since Godel did his work, but Descartes had the disadvantage of being born to early to know about that. In particular, his justifications fall afoul of the third horn of the Münchhausen Trilemma, by resorting to assuming some things as axiomatic. In particular, on reflection I'm baffled that Laplace can take "I think" as axiomatic but not "I am". Existence without though isn't hard to imagine (and some Laplacian demon might be imposing its thoughts on us), but thoughts without existence is. Perhaps if Laplace hadn't set out to prove the existence of God he wouldn't have had to make such odd assumptions.