In the Kant-Fries-Nelson school of thought there is a kind of knowledge that one knows but not by sense perception and not by reason. But this is not emotion either. Nor by structures imbedded in the brain
There is a tendency to understand Fries as ''psychologism'' [all in the mind[. And if that would be all there is to it, then I would not be impressed. But the way Dr. Kelley Ross understands and explains that school in a different way that made a lot of sense to me.
But there is a sort of conflict between this school of thought and Hegel-- which to me seems unjustified since they are dealing with different subjects. Hegel does not deal with how we know things. Empirical versus a priori. Rather with the very structure of reality itself.
So to me both the Kant-Fries and Hegel schools of thought seem important. Kind of like Plato and Aristotle are important, but not that we ought to choose between them. There is something to learn from both.
[As for the best of present day thinkers I would have to go with Dr. Kelley Ross at the Kant Friesian web site .]