"I (and I am guessing most Lesswrongers) generally believe that the seeker of philosophical knowledge is better off just deriving everything fresh from scratch, because of how traditional philosophers manage to make their readings so incredibly long to the point that it becomes literary criticism to figure out what they are saying."
Apply that logic to biology - start deriving fresh from scratch and see how long it takes until you get to mitochondria. Or to keep it within philosophy, apply that logic to ethics - and see how much time you waste hung up on some obscure issue with utilitarianism that Bentham already worked out two hundred years ago.
Philosophy's not like a science with a (mostly) linear progression of accumulating knowledge, but there are endless examples of seemingly commonsensical positions on philosophical questions which philosophers have long ago cut to ribbons and moved past. "Deriving everything from scratch" is intellectual suicide.
(Philosophy majors are often told the apocryphal story of a genius who resolved to derive his own philosophy without "wasting time" on other people's ideas, only to wind up with a midget version of what Kant wrote three centuries ago.)
I'd wager that virtually no person reading this who has mastered the (weirdo, unnecessary) jargon in The Sequences would be unable to master the (weirdo, unnecessary) jargon in contemporary analytical philosophy, if curious.
(Biographical disclosure: I studied philosophy in college so am familiar with the major issues, but have long-since turned to science so there are definitely better authorities on current trends)
Apply that logic to biology - start deriving fresh from scratch and see how long it takes until you get to mitochondria.
To some extent, I wish we would. I wish instead of teaching us about mitochondria in elementary school, we were shown the evidence that lead to mitochondria and asked what we think about it, Maybe not to that extreme, but in general I wish education would shift towards that direction.
In any case, I think it's different when you're dealing with a large body of steadily accumulating empirical evidence. You don't need empirical evidence ...
I did a search about property dualism and I couldn't see much written here on this site.