I think Molyneux's problem is an excellent example of why Kantian thinking (as he is apologetically understood in the 21st century) is so important, even today.

I think Molyneux's problem is an excellent example of why Kantian thinking (as he is apologetically understood in the 21st century) is so important, even today. If you follow a modern Kantian line, one of the most important functions of the brain is to provide a common spatial and temporal framework in which it is possible to represent things (a basis for representation). The brain then does the immensely awful work of creating objects in that spatial and temporal basis out of the mess that it gets from optical, auditory, haptic, olfactory systems, as well as information it gets from very strong beliefs we have about the world (think Piaget - object permanence, objects can't be co-located, folk-physics, etc.) We situate a self in that world, and we populate our surroundings with family members, cardboard tubes, music, clouds, walls - every mundane thing. We even build systems of knowledge using symbols in that world, which is rather remarkable (our folk-physics is not the physics we use for engineering, obviously). Consider the problem of remote-piloting a drone. We are capable of shifting our frame of reference from our eyeballs to our droneballs and back again pretty quickly. Your brain is a complex thing - think of how quickly you are able to translate musculo-skelatal movements of your fingers into the correct inputs for the drone. Or say you're wearing headphones and getting auditory input from the drone: how does your brain realize that the sound of someone saying your name (muffled through the headphones) is coming from your friend standing next to you? There is a sort of representational richness in solving these problems that is easy to overlook. I think we've all had the jarring experience of being woken from a dream by a human voice, or a sound in our home, that had one meaning in the dream and another upon waking. Same auditory input, very different processing, but all part of an attempt to project a world that makes sense of your inputs. Experience is a function of our brain working constantly to unify sensation to create an accurate simulation of what is going on around ourselves. The brain does so in a basis language, and its easy to have the mistaken belief that the basis language of space and time is something that "is just there". It is "just there," in the sense that our simulation works pretty darn well for creating a coherent world that we can navigate, but the brain doesn't get it for free - it assumes that basis. I happen to think that the common basis for locating things in space and time is a large part of what makes language possible (how can all agree that "there's a cat on the mat" (or not)), but that's just a silly personal hunch and not a well-considered position. It was a very common mistake in academia ten years ago to think that humans learn the structure of the world from data. We do, but we require a very strong grammar of representation in order to even begin having what we call experiences that it is possible to organize, or learn from (parallel to language learning).