The Pali for 'awareness' (as you are no doubt aware) is sampajañña. In the Suttas it is frequently linked with 'mindfulness' or sati, in the compound sati-sampajañña,
'mindfulness-and-awareness'. In the Satipatthāna Sutta awareness (of
bodily actions) is included in the section on mindfulness of the body,
so we can perhaps conclude that, while it is not different from
mindfulness, awareness is rather more specialized in meaning.
Mindfulness is general recollectedness, not being scatter-brained;
whereas awareness is more precisely keeping oneself under constant observation, not letting one's actions (or thoughts, or feelings, etc.) pass unnoticed.
Here, to begin with, are three Sutta passages to indicate the scope of the practice of awareness in the Buddha's Teaching.
(a) And how, monks, is a monk aware? Here, monks, in walking to and fro a monk practises awareness; in looking ahead and looking aside he practises awareness; in bending and stretching...; in using robes and bowl...; in eating, drinking, chewing, and tasting...; in excreting and urinating...; in walking, standing, sitting, sleeping, waking, speaking, and being silent, he practises awareness. <Vedanā Samy. 7: iv,211> (b) And which, monks, is the development of concentration that, when developed and made much of, leads to mindfulness-and-awareness? Here, monks, feelings are known as they arise, feelings are known as they endure, feelings are known as they vanish; perceptions are known as they arise, perceptions are known as they endure, perceptions are known as they vanish; thoughts are known as they arise, thoughts are known as they endure, thoughts are known as they vanish. <A.IV,41: ii,45>
(c) Here, Ānanda, a monk is mindful as he walks to, he is mindful as he walks fro, he is mindful as he stands, he is mindful as he sits, he is mindful as he lies down, he is mindful as he sets to work. This, Ānanda, is a mode of recollection that, when developed and made much of in this way, leads to mindfulness-and-awareness. <A.VI,29: iii,325>
The next thing is to sort out a verbal confusion. When our actions
become habitual we tend to do them without thinking about them—they
become 'automatic' or 'instinctive' (scratching one's head, for example,
or blinking one's eyes). We commonly call these 'unconscious actions',
and this usage is followed by psychology and science generally. But this
is a misunderstanding. There is, strictly speaking, no such thing as an
'unconscious action'. The Buddha defines 'action' (kamma) as 'intention' (cetanā), and there is no intention without consciousness (viññāna). An unconscious action is no action at all, it is purely and simply movement
as when, for example, a tree sways in the wind, or a rock is dislodged
by the rain and rolls down a mountainside and derails a train (in this
latter case it is quaintly called, in legal circles,'an Act of God' but if there is no God there is no Act, only the movement of the rock).
In the Buddha's Teaching, all consciousness is action (by mind, voice
or body) and every action is conscious. But this does not mean that
every action is done in awareness—indeed, what is commonly called an
'unconscious action' is merely a (conscious) action that is done not deliberately, that is done unawares. What we commonly call a 'conscious action' is, strictly speaking, a deliberate
action, an action that requires some thought to perform (as, for
example, when we try to do something that we have not done before, or
only infrequently). When we do such actions, we have to consider what we
are doing (or else we shall make a mistake); and it is this considering what we are doing
that constitutes 'awareness'. An action that we do without considering
what we are doing is an action that is done without 'awareness'.
So long as we are awake, obviously enough, there is always some degree
of awareness present, since new problems, large or small, are always
presenting themselves, and we are obliged to consider them (even if only for a moment or two) in order to deal with them. (When we dream, on the other hand, awareness is in abeyance; and it is this very fact that we are unable to look at our dream problems objectively that distinguishes dreams from waking experience. When we are awake we are always aware 'I am awake', but when we dream we are not aware 'I am dreaming'; and, in fact, when we have a nightmare and struggle to wake up, all we are doing is trying to remember [or become aware] that we are dreaming,
and if we succeed we wake up.) But though, unlike in sleep, there is
always some degree of awareness present in our waking life, it is
normally only enough to enable us to deal with unexpected circumstances
as they occur; for the rest we are absorbed in what we are
doing—whether it is the daily task of earning a livelihood, or our
personal affairs with our emotional attitudes towards other people
(affection, dislike, fury, lust, boredom, and so on), it makes no
difference. To maintain a detached attitude is difficult when there is
much routine work to be done in a hurry, and it robs our personal
relationships with others of all emotional satisfaction. We prefer to
get through our work as quickly and with as little effort as possible,
and then to wallow in our emotions like a buffalo in a mud-hole.
Awareness of what we are doing, which is always an effort, we like to
keep to the absolute minimum. But we cannot avoid awareness altogether,
since, as I remarked earlier, it is necessary in order to deal with
unexpected problems, however insignificant, as they arise.
But this awareness is practised merely for the purpose of overcoming
the obstacles that lie in the path of our daily life—it is practised
simply in order to get through the business of living as expeditiously
and as efficiently as possible.
Awareness in the Buddha's Teaching, however, has a different purpose:
it is practised for the purpose of attaining release from living. These
two different purposes, while not directly opposed, do not in fact
co-operate—they are, as it were, at right angles to each other; and
since the amount of awareness that can be practised at any one time is
limited, there is competition between these purposes for whatever
awareness is available. Thus it happens that in activities requiring
much awareness simply for their successful performance (such as writing
this letter) there is not much scope for the practice of awareness
leading to release (though no doubt if I got into the unlikely habit of
writing this same letter twice a day over a number of years I should be
able to devote more of the latter to it).
The Buddha tells us (in the Itivuttaka III,30: 71-2) that three things harm the progress of the sekha bhikkhu (one who has reached the Path but who has not arrived at arahatship):
fondness for work (i.e. building, sewing robes, doing odd jobs, and so
on), fondness for talk, and fondness for sleep. In the first two, as we
can see, much awareness must be devoted to successful performance of the
task in hand (making things, expounding the Dhamma), and in the third
no awareness is possible. From the passages I quoted earlier it is clear
that awareness for the purpose of release is best practised on those
actions that are habitual and do not require much thought to
perform—walking, standing, sitting, lying down, attending to bodily
needs of various kinds, and so on. (The reference to 'sleeping' in
passage means that one should go to sleep with awareness, bearing in mind the
time to awaken again; it does not mean that we should practise awareness
while we are actually asleep.) Naturally a bhikkhu cannot
altogether avoid doing jobs of work or occasionally talking, but these,
too, should be done mindfully and with awareness as far as possible: 'he
is mindful as he sets to work', 'in speaking and being silent he
practises awareness'. The normal person, as I remarked above, does not
practise awareness where he does not find it necessary, that is to say,
in his habitual actions; but the bhikkhu is instructed not only
to do these habitual actions with awareness but also, as far as
possible, to confine himself to these actions. Drive and initiative in
new ventures, so highly prized in the world of business and practical
affairs, are impediments for one who is seeking release.
And how does one practise this awareness for the purpose of release? It
is really very simple. Since (as I have said) all action is conscious,
we do not have to undertake any elaborate investigation (such as asking
other people) to find out what it is that we are doing so that we can
become aware of it. All that is necessary is a slight change of
attitude, a slight effort of attention. Instead of being fully absorbed
by, or identified with, our action, we must continue, without ceasing to
act, to observe ourselves in action. This is done quite simply
by asking ourselves the question 'What am I doing?' It will be found
that, since the action was always conscious anyway, we already, in a certain sense, know the answer without having to think about it; and simply by asking ourselves the question we become aware
of the answer, i.e. of what we are doing. Thus, if I now ask myself
'What am I doing?' I can immediately answer that I am 'writing to Mr.
Dias', that I am 'sitting in my bed', that I am 'scratching my leg',
that I am 'wondering whether I shall have a motion', that I am 'living
in Bundala', and so on almost endlessly.
If I wish to practise awareness I must go on asking myself this
question and answering it, until such time as I find that I am
automatically (or habitually) answering the question without having to ask it.
When this happens, the practice of awareness is being successful, and
it only remains to develop this state and not to fall away from it
through neglect. (Similar considerations will of course apply to
awareness of feelings, perceptions, and thoughts—see passage.
Here I have to ask myself 'What am I feeling, or perceiving, or
thinking?', and the answer, once again, will immediately present
itself.)
The objection is sometimes raised that it is not possible to do two
things at once, and that it is therefore not possible both to act and to
be aware of the action at one and the same time. But this opinion is a
pure prejudice, based upon a certain false notion of the nature of
consciousness (or of experience). It is perfectly possible to be doing a
number of things at the same time (for example, I am breathing as I
write this letter, and I do not interrupt the one in order to do the
other); it is not possible to devote equal attention to all of
them at the same time, but this is another matter. And this is true also
of acting and being aware of the action. This can be verified very
simply; all that is necessary is to start walking and, while still
walking, to ask oneself the question 'What am I doing?'; it will be
found that one can give oneself the answer 'I am walking' without
ceasing to walk (i.e. it is not necessary to come to a halt, or break
into a run, or fall down, in order to answer the question).
Why should one practise awareness? I can think of three good reasons immediately, and there are doubtless others besides.
In the first place, a person who is constantly aware of what he is doing will find it easier to keep his sīla.
A man who, when chasing his neighbour's wife, knows 'I am chasing my
neighbour's wife', will not be able to conceal from himself the fact
that he is on the point of breaking the third precept,[2]
and will correct himself sooner than the man who chases his neighbour's
wife without considering what he is doing. In brief, awareness leads to
self-criticism and thence to self-correction.
In the second place, awareness is cooling and is directly opposed to
the passions (either lust or hate), which are heating (this has no
connexion with the mysterious qualities that are inherent in Oriental
food, but missing from food in the West). This means that the man who
constantly practises awareness has a powerful control over his passions;
indeed, the constant practice of awareness actually inhibits the
passions, and they arise less and less frequently.
In the third place, the practice of awareness is an absolute
pre-requisite for the understanding of the essence of the Buddha's
Teaching. The reason for this is that the Dhamma is concerned not with
any one single experience (consciousness, feeling, etc.) as such, but
with experience (consciousness, feeling, etc.) in general. We do not
need the Buddha to tell us how to escape from any particular experience
(whether it is a simple headache or an incurable cancer), but we do need
the Buddha to tell us how to escape from all experience whatsoever.
Now, in the normal state of being absorbed by what we are doing (that
is, of non-awareness) we are concerned only with this or that particular
experience or state of affair ('she loves me; she loves me not...'),
and we are in no way concerned with experience in general ('what is the
nature of the emotion of love?'). But when we become aware of what we
are doing (or feeling, etc.), the case is different. Though we are still
doing (or feeling), we are also observing that doing or feeling with a
certain degree of detachment, and at that time the general nature of 'doing' and 'feeling' comes into view (the particular doing and feeling that happen to be present now merely appear as examples
of 'doing' and 'feeling' in general); and it is when this general
nature of things comes into view that we are able, with the Buddha's
guidance, to grasp the universal characteristics of anicca, dukkha, and anattā. But here we are getting into deep waters, and I do not wish to add difficulties to a subject that is already not very easy.