As mentioned before, concentration can produce great stability of mind, and this can lead to equanimity. Equanimity is that quality of mind that is okay with things, or balanced in the face of anything, even a lack of equanimity. This may sound a bit strange, but it is well worth considering. Equanimity also relates to a lack of struggle even when struggling, to effortlessness even in effort, to peacefulness even when there is not tranquility. When equanimity is really well-developed, one is not frightened of being afraid, worried by being concerned, irritated by being irritated, pissed off at being angry, etc. The fundamental nature of the mind is imperturbable and absolutely equanimous; phenomena do not disturb space or even fundamentally disturb themselves from a certain point of view.
There are actually whole spiritual traditions that involve just tuning into this basic truth. There can be great value in learning to see the space around things, rather than just being caught up in the things themselves. A useful phrase from one of these traditions is “cultivating space-like meditative equipoise.” The more we habituate this way of being, the more we connect with the truth of our minds.
There are also some really excellent teachings, especially from Zen and Daoism (also spelled Taoism) that relate to this, such as the teachings about no defilements, no enlightenment (or practice is enlightenment), nothing to perfect, no where to go, etc., and checking in with some of these teachings can be very helpful. This is the important counterbalance to spiritual striving and gung-ho practice that can get very future-oriented if done incorrectly. In the end, even if you have all kinds of insights, if you don't have equanimity you will be beating your head against a wall, and it actually might feel like that or worse.
Once again we are back to knowing this moment just as it is. This “just as it is” quality is related to mindfulness and also to equanimity. In the end, we have to accept the truth of our lives, of our minds, of our neuroses, of our defilements, of impermanence, of suffering, and of egolessness. We have to accept this, and this is what they are talking about when they say “just open to it,” “just be with it,” “just let it be,” “just let it go,” and all of that.
From a pure insight practice point of view, you can’t ever fundamentally “let go” of anything, so I sometimes wish the popularity of this misleading and indifference-producing admonition would decline, or at least be properly explained. However, if you simply investigate the truth of the Three Characteristics of the sensations that seemed to be a solid thing, you will come to the wondrous realization that reality is continually “letting go” of itself! Thus, “let it go” at its best actually means, “don’t give a bunch of transient sensations an excessive sense of solidity.” It does not mean, “stop feeling or caring,” nor does it mean, “pretend that the noise in your mind is not there.”
If people start with “just open to it” and yet don't develop strong mindfulness, look into the Three Characteristics and gain deep insights, then their practice may be less like meditation and a lot more like psychotherapy, daydreaming, or even self-absorbed, spiritually-rationalized, neurotic indulgence in mind noise. It was noticing the high prevalence of this activity and the pervasive and absurd notion that there was no point in trying to get enlightened that largely demolished my vision of being a happy meditation teacher in some mainstream meditation center somewhere.
Psychotherapy, on the other hand, can be a fine undertaking, but it is a completely different endeavor from meditation and falls squarely in the domain of the first training. I do not, however, advocate wallowing in self-absorbed mind noise, and anyone who has been to a small group meeting on a meditation retreat knows what I am talking about. This is what happens when people don’t ground the mind in the object of meditation.
On the other hand, even if you gain all kinds of strong concentration, look deeply into impermanence, suffering and no-self, but can't just open to these things, can't just let them be, can't accept the sometimes absurd and frightening truths of your experience, then you will likely be stuck in hell until you can, particularly in the higher stages of insight practices.
Reflect on these previous three paragraphs now and often, as many, many errors on the spiritual path come from not understanding the points made therein. Too often there is an imbalance between the first three (mindfulness, investigation, and energy), and the last three (tranquility, concentration and equanimity). The vast majority of aspiring insight meditators are, to be honest, way, way, way too slack about the first three. Just so, some gung-ho meditators get into trouble when they don't cultivate enough acceptance, balance and peace, related to the second three. When people focus only on the middle factor, rapture, they become vapid bliss-junkies. In short, all seven factors are very important.
The order here is important. Start with good technique, mindfulness, investigation, etc., and work on the others along the way. In summary, you must have both insights and acceptance, and each perspective can and should help the other along the way. They are actually one and the same.
One last thing about equanimity: its near enemy, its deadening imposter, is indifference. Real equanimity is accepting of the full range of the heart and experience, whereas indifference is dry, flat and heartless. This point is frequently misunderstood. However, being accepting of the full range of the heart doesn't mean always acting on whatever impulse comes up. Act only on the impulses of the heart that seem skillful and kind.
To balance and perfect the Seven Factors of Enlightenment, you guessed it, is sufficient cause for awakening. Thus, checking in from time to time with this little list and seeing how you are doing and what might need some improvement is a good idea, and just having this list in the back of your mind somewhere can be helpful.
It is important to note that only one factor, investigation of the Three Characteristics, separates training in concentration from training in fundamental insight. When purposefully training in concentration, we decide to be mindful of a limited and specific concentration object, such as the breath or even a rarified state of consciousness. We do not, however, investigate the individual sensations that make up that state, as it would break apart under that investigation and produce insights. If we are not looking for ultimate insights at that point in time, then we should avoid investigating that state. However, we do apply energy to stabilize our concentration, and this produces rapture, a characteristic of the early concentration states. We also cultivate concentration very strongly, obviously, and also tranquility and equanimity, which help us stabilize early states and attain to higher ones. Thus, six of the Seven Factors of Enlightenment are cultivated by training in concentration, and it is often recommended as a preliminary training before training in insight, for this and other reasons.
Training in morality also cultivates some of the Seven Factors of Enlightenment, though in a less formally meditative way. In order to work well in the ordinary world, it is very helpful to be mindful of what we are doing, saying and thinking and also what effects these produce in the world so that we can consciously work to craft the life we want to lead as best we can. It is helpful to exert energy as we craft our life for obvious reasons. We can also cultivate tranquility, the ability to not take life too seriously, to relax, finding that balance of focus and ease that makes for a good life. We can learn to concentrate on staying on track with our tasks, goals and aspirations, though in this case concentration is more like a form of discipline than the concentration of formal meditation, though discipline of action, speech and mind is vital for the other two trainings. Finally, we can learn that we cannot get rid of all of the bumps on our road, so having the shock absorbers of equanimity, the ability to stay spacious and accepting of what happens, is also very helpful for crafting a good and healthy life.