Again, how does the 'my choice of school' node here differ from the 'my not being born into a cult' node? The latter doesn't cause philosophical truths either.

Right, it doesn't. But they're still going to be inferentially connected (d-connected in Judea Pearl's terminology) because both a) your beliefs (if formed through a reliable process), and b) philosophical truths, will be caused by the same source.

And just a terminology issue: I was being a bit sloppy here, I admit. "X causes Y", in the sense I was using it, means "the state of X is a cause of the state of Y". So it would be technically correct but confusing to say, "Eating unhealthy foods causes long life", because it means "Whether you eat unhealthy foods is a causal factor in whether you have a long life".

(Strictly speaking nothing does: only contingent things have causes, and philosophical truths aren't contingent on how things turn out. But let's put that aside for now.)

Yes, I assumed that how philosophers define the terms, but a) I don't find such a category useful because b) of all the instances where philosophers had to revise their first-principles derivations based on subtle assumptions about how the universe works.

What [my education in philosophy] does is provide me with habits of thought that do a better job of producing true beliefs than the mental habits I would have acquired if born into a cult. But then different schools of philosophy teach different habits of thought too (that's why they reach different conclusions). The flaws in the other schools of thought are much less obvious than the flaws found in cults, but that's just a difference in degree...

I actually agree. Still, to the extent that they do converge on reliable truth finding mechanisms, they should converge on the same truth-finding mechanisms. And one's admission that one's own truth-finding mechanism is so heavily school-dependent would indeed be quite worrisome, as it indicates insufficient critical analysis of what one was taught.

Of course, merely being critical is insufficient (someone who said so in this discussion was rightfully modded down for such a simplistic solution). I would say that you additionally have to check that the things you learn are multiply and deeply connected to the rest of your model of the world, and not just some "dangling node", immune to the onslaught of evidence from other fields.