Why is there no boundary to consciousness, no surface at the edge of mental space through which new ideas come, even though new ideas do come into mental space all the time? Sometimes you say, 'this idea just popped into my head' - how did that happen, what was it like? You suddenly found yourself thinking it as if you were already doing so a moment before you noticed that you were. And what you recognised was its incongruity with what you had been thinking before. You started with an implicit sense of the range of ideas that were available, or that you were capable of producing, you knew that pretty well. And then suddenly a new thought arose, something quite fresh, perhaps the solution to a problem. It is mysterious the way that it got there, but it was you that produced it, it came up from right inside your mind but at the same time with a quality of otherness or impersonality. If there was something you knew it was how to seize it in the bud. You might say it was a little bubble of intelligence that you gathered up in a quick gesture. You were already thinking it before knowing that you were doing so. So if there is a boundary it is between what you know and what you know you know; as if these are two different orders of mind; and also between what happens fast and what happens slow. The fringe of mind is this in pre-reflective consciousness - impossible to say how far, how deep it goes, but it is always happening.