Whenever anyone takes up the study of a subject, they endeavor to obtain the clearest, most inclusive explanations of that subject that they are able to obtain in order to get an accurate and truthful conception of the material at hand. In the case of general subjects like meditation (and Buddhist meditation in particular) it can be somewhat confusing and frustrating to have to sift through differing accounts describing meditation instruction. Especially when one comes across instruction from different sources that are either dissimilar or that contradict one another. For how is someone who is new to the practice able to weed out the truth from the misperceived with regard to what is being stated?
The only answer to this question is: through one's own direct experience. Yet, even that, at times, can become confusing, as things are liable to change (or at least our perception of them is) as their development matures. This is no different with meditation than it is with other subjects which are liable to subjective opinion. For the most part, the path (the Noble Eightfold Path) that the Buddha laid out for others to practice in order to arrive at the same realizations as he had is rather straightforward and unambiguous. At least as far as it goes when dealing with the larger issues of right view, right thought, right speech, right action, right livelihood, right effort, and right mindfulness. It's when we get to the area of right concentration, the area dealing with meditation, that things can become a bit confusing if we are not given the correct conceptual maps with which to deal or are unable properly to discern the ones we are given.
One of the most difficult subjects to teach in Buddhist meditation is the practice of absorption (also known as jhana). Not because absorption itself is necessarily difficult to achieve. But because it can be difficult to get a conceptual handle on if one has not been able to connect the experience to something that they have experienced in their past. I contend that virtually everyone has, at one time or another in their life, experienced absorption (at least the first level) whether they were aware of it or not. From this point, as an instructor, it's just a matter finding an experience that the person can relate to in order to communicate to them what absorption "feels like" when they experience it. Once they get the idea, then you have something to work with.
One of the other hindrances to being able to recognize absorption when it is occurring is thinking that one has to be able to recognize the factors for absorption: vitakka, vicara, piti, and sukkha, and how these change from one level of absorption to the next higher level as they are utilized for a unification of the mind on an object. In a perfect world, while it would be nice to be able to recognize these factors when we're first starting out, the fact of the matter is that the mind of the beginning practitioner is likely not settled enough (still enough) to always be able to adequately identify these subtle factors. Therefore, it is probably best not to fret over one's inability to identify these factors in the beginning. The most important thing is to be able to find a way to enter absorption at will whenever one wishes and to recognize that this has occurred. We can work on noticing the details later.
Now, this isn't meant to be an essay about the nuts and bolts of practicing absorption. It is meant to address an issue regarding the perception of instruction and how that perception can be manipulated by the language used in description. The English language can tend to be rather harsh and unforgiving in its written form. Ideas can seem to be set in stone just in the course of composing a description of a phenomenon that is constantly in flux and therefore subject to change, such as the present subject matter of the mind and its relationship to the practice of meditation.
When these descriptions become cauterized by tradition, they can seem to be almost impossible to break through in order to rediscover the actual truth of the matter. In other words, the mind accepts one description as being unalterable truth, and then shuts down to the possibility of any change or alteration of that description which might occur in actuality. What this presentation will endeavor to accomplish is to explore some aspects of the experience of absorption in order to arrive at a more fair (and hopefully more fact-based) conceptual template of this experience.
This isn't meant to be combative or to offer up for debate any of the ideas express here. It's meant to allow others, who might perhaps have had similar experiences to the ones being described, a place to voice the discernment of their experiences and to confirm, correct, or add to the possibilities being explored here. Hopefully, people long in the tooth with absorption experience, like Geoff and possibly even Tilt and Kenshou, will contribute their impressions.
One of the first (and most important) lessons I learn from a former spiritual preceptor was that if I was going to speak at all, I should speak only from my own experience of the matter under discussion, and not make things up that I had not experienced in order to forward my own view of the matter. If you speak only from your own experience, there may be occasions in which you are not able to speak at all (on account of a lack of experience in the subject matter). This acts as a kind of filtering mechanism, to filter out biases and prejudices (as well as preconceived ideas that haven't been tested in actuality) so that they do not get in the way of the facts under discussion. It would be good if those who respond to this thread would keep this in mind before they post here.
"The gift of truth exceeds all other gifts" — Dhammapada, v. 354 Craving XXIV