Chris in a comment asks a question that might be of interest for others:
Jack, are there other passages elsewhere in Rinpoche’s work where he addresses the issue of the not-knowing that arises with the perceptual-level polarities? I’m exploring that sense of deficiency of knowledge, the kind that tries to bridge the ‘gap.’ – Christopher.
I know the TSK books fairly well, but I had no answer to that question. However, I do have the CD that contains the text of all the books. I did a search there for “polar.” As a result, I suggest you look at the chapter called “Not-Knowing” in KTS, starting at p. 259. You could also take a look at Topics 5 and 6 in the TSK “Guide” in When It Rains.
Chris’ description of the distance set up by polarity is exactly right, it seems to me.