There are two moves with the a priori:
It’s a priori for some reason (by defintion, by meaning, by logic/math), but does it map to reality?
You secure the a priori via a posteroi means. Now, given this constraint we assume, what follows?
Now, philosophers (and people in general) focus on the two extremes:
- “How do we secure our foundations?” This actually led to the program of 20th century math, which has lead to a ton of crazy stuff, so I’d say it actually was a success.
- “What if we need to go doubt everything?” I don’t count pragmatists out of this, by the way. Pragmatists who accuse “Cartesians” of needing absolute security but then go around parading fallibilism are a cancer.
- Bayesians are not good either, because they try and subsume everything under probability.
What actually happens in proper thought engineering is, you have an “a priori” thought. This thought suffers both from:
Not being able to map the entire space. You don’t even know the entire space, can’t say it, can’t give any universal solution to it.
Not being able to secure foundations. Even if we grant logic/math as a secure foundation, real engineering often must bring in (knowingly) “a posteroi” elements.
This is actually just entirely fine. You build this stable capacity in space ; it doesn’t solve many problems, and you don’t even know if it solved the problem “it claimed” to solve. That’s fine. You created something from nothing.
The issue with this is that, while other theories of knowledge tend to try and universalize in their statements, the patchwork ones like these turn into spaghetti and meatballs.