In meditation we broadly have insight practices and concentration practices. There are plenty of other things that don’t fit too tightly in either category, but most are pretty well one or the other. Noting practice, where you take experience and label the sensory categories like sight, sound, and touch, is a classic insight practice. Jhana practice, where you attend to a feedback loop of increasing pleasure while releasing unconscious feedback loops, is a classic concentration practice.

The unifying feature of insight practices is the focus on the three characteristics. These are translated oddly much of the time, but a roughly correct rendition of them is change, to be lacking inherent essence/empty, and dissatisfaction/tension. The unifying feature of concentration practices is the focus on the duals of the three characteristics. The duals are roughly stability, having essence, and satisfaction/compression.

I speak loosely here in regard to what the 3Cs and the duals are. In one way of looking, these are ontologically foundational characteristics of sensations. In another way, these are productively described as counters to maladaptive strategies that the mind uses because it is confused about some relatively fundamental aspects of reality. I like the latter a lot, especially for practice, but I mostly use the former here. More on the other way of seeing in other posts.

In the case of compression and tension specifically, I mean something closely related to the implementation of compression of information in the mind. Compression occurs when you notice some symmetry and can reduce the complexity of your world model. Tension occurs when you are trying to do this, but apparently can not manage it for whatever reason.

Given all that, insight practices are typically about seeing the tension in things, the emptiness of them, and watching them flux. Concentration practices are about increasing attentional stability, perceiving the essence of things, and feeling satisfaction when things click together.

This is a rough categorization, and the domains of insight and concentration are inseparable from each other due to the inseparability of the 3 characteristics from their duals. To change there must be some form of stability, and vice versa. For there to be essence of something, other stuff must be nonessential. For there to be compression of information, there must be some tension to pull the information together.

It’s also possible to take any natural phenomenon and slice it in terms of the three characteristics and their duals. This is just because they are pretty convergent categories, and analyzing things like this won’t get you much closer to classical enlightenment and large reductions of perceptual tension, but it is very cool and can lead to typical insights about things. We have entire mathematical disciplines about studying change, namely differential equations. I personally suspect that there is a lot of interesting meditation that could occur with more formal scaffolding in PDEs.

There are also open questions in regard to the nature of the three characteristics. For one, why are there three? Are there sets of two characteristics, four? More? Another very curious thing is that attention of high enough quality and quantity on the three characteristics will reliably lead to meditative cessation (experience stops, total jump-cut in time), with distinctive intro phenomenology that seems to depend on which characteristics you are mainly paying attention to. Why this phenomenology happens is an open question to me, why there are six doors is open, and relating the structure of the doors is likely a productive endeavor for deeper insight into the mind.