According to realism there are minds and mind-independent objects. Minds can know these objects. Kantianism also has it that there are minds and mind-independent objects. But these minds cannot know these objects. Idealism asserts that there are only minds. Objects are mind-dependent constructions and known to be such. According to what I call here the epistemic stance there are minds. But we cannot get "outside" our minds. So we do not know whether there are mind-independent objects. And if there are such objects, we do not know whether they are similar to the objects grasped by our minds.
The position I am myself committed to I call here the meta-epistemic stance. According to this view the distinction between "minds" and "mind-independent objects", between the "inside" and the "outside", is itself only justified as a human-relative distinction. The world-in-itself might not even consist of a formal distinction between "minds" and "mind-independent objects". For all we know, the distinction between "inside" and "outside" might not even apply to the-world-in-itself. We will never be able to access the world-in-itself. Absolutely everything we say can only be justified as a claim about the world-for-us. Moreover, even the very distinction between the-world-for-us and the-world-in-itself is merely justified from within the-world-for-us from which we can never escape. I have developed this meta-epistemic stance in detail in various earlier texts.