What follows is Ven Bodhi's explanation of bare attention and sati in his dialogue with B. Alan Wallace, found here: http://shamatha.org/content/corresponde ... kkhu-bodhi
As a wholesome mental factor, sati is consistently explained in the same way as in the quotation from Vism XIV 141 (with the forms saranti, sarati, saraṇa, simply cognates of sati). So I don’t have any new definition of sati to offer. But I hope that I can explain how sati, as “bare attention,” can function as a wholesome mental factor. When I use the word ”awareness” or “attention” to render upaṭṭhāna, as representing sati in this role (which is just my hypothesis), this awareness is quite different from ordinary consciousness (viññāṇa), and this attention is different from manasikāra, the mental factor that performs the function of adverting to an object or selecting features of the objective field for closer focus. Sati, as bare attention, is never completely bare. When practiced in the full context of the noble eightfold path (even the path-practice of a worldling) it is, or should be, embraced by other factors of the path, most notably by right view, right motivation, and right effort (factors 1, 2, and 6); it is already supported by the three morality factors (3, 4, 5). As Ven. Nyanaponika first used the expression, sati is “bare” in that it is shorn of our usual emotional reactions, evaluations, judgments, conceptual overlays, etc., and is intended to lay bare the experienced object as clearly as possible.
We should remember that sati, in the context of satipaṭṭhāna practice, is always practiced as part of an’anupassanā,’ and this word helps to bring out the role of sati. We usually translate ‘anupassanā’ as “contemplation,” thus ‘kāyānupassanā’ as “contemplation of the body,” but this might be somewhat misleading. It might be more accurate, and more literal, to translate it as “observation.” The word is made up of a prefix ‘anu’ which suggests repetition, and ’passanā’, which means “seeing, viewing.” So sati is part of a
process that involves a close, repetitive observation of the object.
Several factors enter into anupassanā. According to the “satipaṭṭhāna refrain,” these are energy (ātāpī, “ardent”), clear comprehension (sampajāno), and mindfulness (satimā). Energy contributes the strength to fulfill the practice, but it is mindfulness that brings the object into the field of observation, and in many exercises (though not all) it does so simply through the act of attending to the object over and over, as simply as possible, and of attending to each object that presents itself on the successive occasions of experience. Mindfulness, as bare attention, is thus a key element in the process of adopting an “observational stance” towards one’s own experience.
Mindfulness, as bare attention, however, isn’t just floating loosely in a void. In a meditative situation it will be anchored in a primary object, such as in-breathing and outbreathing, or the rise and fall of the abdomen. But whenever some other phenomenon arises and floats into the field of awareness, the meditator is advised to simply note it, without reacting to it, and then to bring the mind back to the primary object. If any reactions take place, such as enjoying the distracting object or feeling irritated by it, one should note the enjoyment or irritation, and again return to the primary object.
Thus, if you have trouble seeing mindfulness–as bare attention–as a wholesome mental factor because it isn’t remembering one’s wholesome qualities or attending to bodhipakkhiya dhammas, the same problem could be posed in terms of mindfulness of breathing. A skeptic might say: “Yeah, I can see loving-kindness meditation, or compassion meditation, as a wholesome state, but mindfulness of breathing, why, you’re doing nothing but following your breath in and out. What could be especially ‘wholesome’ about that?”
In the practice of bare attention, as used in the ”dry insight” system of vipassanā, mindfulness is used to note whatever is occurring on successive occasions of experience. As this is practiced continuously, over extended periods of time, the mindfulness builds up momentum. By means of this momentum, it is able to bring the “field of experience” into increasingly finer focus, until one can tune into the precise factors constituting any occasion of experience and distinguish them according to their place among the five aggregates. In this way, mindfulness paves the way for the discriminative understanding of the “constituted nature” of experience, allowing paññā to move in and discern the threads that make up the complex experiential occasion. Then because one is attending to the unfolding of experience sequentially across occasions of experience, the characteristic comes into sharp focus. One can see how each event occurs and vanishes, followed by the next event, which occurs and vanishes, followed by the next event, which occurs and vanishes. As concentration grows stronger, this ability to focus upon the arising and passing of events becomes more refined, so that it seems one is perceiving the arising and passing of cognitive events in terms of nanoseconds. Again, this uncovers, even more starkly, the characteristic of impermanence, and from there one can move on to the characteristics of dukkha and anatta.
Of course, one who gains the jhānas, and then uses the concentration of the jhāna to focus on the procession of experience, has even more powerful resources for gaining direct perception of the radical truth of impermanence. But even this must begin with some degree of “bare attention” to immediate experience.
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“Sati, as bare attention, is never completely bare. When practiced in the full context of the noble eightfold path (even the path-practice of a worldling) it is, or should be, embraced by other factors of the path, most notably by right view, right motivation, and right effort (factors 1, 2, and 6); it is already supported by the three morality factors (3, 4, 5).”
You were worried that I had missed out on right thought, and further on in your letter you expressed concern about the need for proper motivation; but the factor often translated as right thought, sammā saṅkappa, is what I have here translated “right motivation” (it is elsewhere translated “right intention”). I’m not sure how the Tibetan translations render the second path factor, but the Pāli term suggests the purposive, motivational element in thought, rather than the cognitive, which is covered by right view. In my understanding, without right view or right intention, one could be practicing “bare mindfulness,” and yet that “bare mindfulness” is unlikely to develop into sammā sati, right mindfulness. Similarly, one could be practicing mindfulness of breathing, or contemplation of bodily sensations, or loving-kindness meditation, or perhaps even reflective meditation on the Four Noble Truths and dependent origination as applicable to this present life alone (no trespassing into unverifiable past and future lives), and these practices, while being “wholesome,” would still be deficient as Dharma practices.