With what sense can we perceive thinking? Not with eyes or ears, that is clear enough. When we try to grasp thinking for the first time, it is thought what we see: contents. We know what we are thinking when we are healthy persons. It is consciousness that makes us know what we are thinking. Or, to put it the other way round: because we know what we are thinking, we are conscious.
But this is not the process of thinking, not the activity of thinking that we perceive. If we try to grasp thinking as an activity, we need another specific sense, we could say an 'inner sense'.
At first we have to remember what we did, we don't succeed to see thinking while thinking. We have to do exercises to think actively and then try to remember what exactly we have done while thinking. The same 'sense' that makes it possible to have memories gives us the power to remember how we have thought - although it takes more inner energy to do so. It takes time to awaken our thinking, and we will not manage at the outset both to think and at the same time perceive the act of thinking. The thoughts are over when we turn our gaze to thinking. But trying to get hold of the process of thinking while thinking awakens a new sense, the 'inner sense'. Something is absolutely certain: the sense that perceives the act of thinking in the present – rather than from memory - is also thinking. The 'eye' with which we regard thinking as an activity is thinking itself.
Two things we can learn to see here. First that we ourselves generate every concept, every analysis and synthesis, every logical movement in thinking. Although thoughts as a content can be given - that is, where we don't create the content - they must be thought if we want to know that we have them. And we cannot think something that is unthinkable. So it is a rather shocking thing to get used to the experience that thinking is brought about by me, and only by me. Not the contents, but the 'knowing' activity.
The second observation in thinking about thinking is that we are true artists of thinking, that we know thoroughly how to do it - although we never realize this, and wouldn't ever realize it, if we hadn't started trying to perceive thinking by thinking.
Feniks, Aberdeen Bestiarium.