The approach to Kant called the Friesian School does not engage with the major interpretations of Kant. It sort of stands alone  ''Take it or leave it.'' as you might hear when you go to buy at the supermarket. I think this isolates this school from academia, and also makes it hard to place in the Kantian Spectrum. I mean to say that the major interpreters of Kant are Cohen [Marburg school], Allison, Strawson, Sellers. [The later Cohen diverged from Kant.] And besides them, there are the many approaches influenced by Kant--like the later Cohen. Where does immediate nonintuitive knowledge [of the Friesian school] fit or not fit with all this? In what areas do they agree, and in what areas disagree and why? More to the point--Leonard Nelson himself diverged from Fries. Fries did originate the idea of a third source of knowledge, immediate non intuitive, but he was thinking that it is implanted in the brain. That was nothing like Nelson or Kelley Ross at all. With Nelson, you have to have beginning axioms. But there again comes the question that Nelson never asks or deals with: How do you know they are true? To answer this question come Kelley Ross with the idea of Karl Popper of falsification. I.e., to prove an idea, you do not need more evidence. Rather, you need a possible counter example, and then to test the idea. [Background--to Kant there are two sources of knowledge sensibility and or concepts. These two things were radically divided by Berkeley and Descartes. Kant’s job as he saw it was how to get these two back together. He succeeds by apperception. the self. that is that physical sensibility would have no meaning for a person unless the self was able to put them together] ], but how can you put sensibility together with concepts where are is no sensibility i.e., the second part of metaphysics--the universe as a whole, time as a whole, God, etc. so to Kant there is no knowledge of metaphysics in its second part.