Hi IanAnd,
thank you very much for the description of your experiences. They are very helpful to me. I guess lately I have spend a bit too much time with the Pure Insight Path, trying to understand some things. But in the end I am not a suddha-vipassana-yanika but a samatha-yanika and there are some experiences and insights on the Pure Insight Path I never had and will never have due to this fact. So it feels good to know there are others, whose experiences are more similar to mine. Maybe you can relate at least to some of them.
Like you I started with Hindu meditation (it was hatha yoga, though) more than 30 years ago. It was during my early teens and my practice duration was one to two hours every day. Guess, I was some kind of addicted to it. But it was so much fun and it was so fascinating to look into oneself, one's mind and body - go where one had not been before, if you know what I mean.
Concentration is like a muscle, the more one trains it the stronger it becomes. But when one lessens the training the muscles will become weaker, too. So at that time I spend much time on workout of this muscle - the pleasant sideeffect of increase of general concentration during every day life was only stimulating. However, after some time my mind spontaneously entered states of concentration I didn't know what to make of. I don't know for sure if one of them was, f.e. the infinite space jhana but some descriptions I find on jhana are close. In my experience (and it looks like we differ here) during this state of concentration there were no body sensations (no sounds, no tactile impressions, no smells, etc) nor thoughts, images and so on. The impression of, say, infinite space dominated the mind completely, suppressing everything else.
But then again there was something else, something new. For the first time I knew what was going on in my mind the moment it did. When the state broke and I was "Freawaru" again (and not infinite space) I could only see it in retrospect. And I realised that in general I could only see my mind and body in retrospect, too. I didn't like that. So, while I felt a bit scared of the states of concentration because I had never heard about them and didn't know what they were, I liked that Knowing. Sometimes on this forum the question arises "what is the difference between mindfulness and Insight?" - maybe it is more difficult to see for a suddha-vipassana-yanika but for me it is obvious: during these kind of states mindfulness was present. There was the ability to see the mind in the present, like an eye that was open or a light that shone. But that itself is not identical to Insight. Mindfulness is like a kind of tool and one has to use that tool to gain Insight. Insight requires not only mindfulness but also will, investigation, analysis, memory and a number of other faculties. And I couldn't access them during the states of concentration as they were suppressed. At least at first. Later there was something new and strange: there was will, investigation, analysis, memory and so on, but they were quite different than those of the Freawaru personality. I still don't know what to make of this.
And luckily I didn't have to. One day I returned from such a state of concentration and mindfulness didn't cease. I still knew what was going on in my mind (and also body, a new idea for me at that time) the moment it was going on. I stopped my practice of these states then: you might say I got what I wanted from them: mindfulness. For some years the states would still happen on their own now and then but without practice it became lesser and lesser.
Presently, I don't practice states of absorption. I limit myself to Insight (the reason why I investigated the Pure Insight Path). My main practice is to investigate the mind during every day activity like Bhate G suggests here:
You can be mindful while solving problems in intensive calculus. You can be mindful in the middle of a football scrimmage. You can even be mindful in the midst of a raging fury.
http://www.vipassana.com/meditation/min ... ish_16.php" onclick="window.open(this.href);return false;
However, even during these non-jhanic state I observe a change regarding the senses. Like you said when one is absorbed in a good book (or calculus, etc) the other senses lessen. So I investigate how they lessen, even become so suppressed that they are absent, and how they "return". Some time ago I tried anapana sati (the version of concentrating on one's tactile impression of the nostrils) and even though I stopped at access concentration (using the definition given here
http://www.leighb.com/jhana2a.htm" onclick="window.open(this.href);return false;), analysing it I found out that I didn't experience any sounds or smells during this state (tactile impressions were still there, though).
I know there are several definitions of jhana and maybe my experiences of complete absence of the senses was not jhana but I think in the end this does not really matter. What matters - in my opinion - is that through them I gained that tool called mindfulness. Like you.