A meditation on sampajanna; mindfulness or wisdom…
Vipassana Research Institute
There are several technical terms in Pali  which are of significance, both in the field of pariyatti (theory) and patipatti (practice). One such word is sampajanna.
This term often occurs along with sati in the expressions such as ’sati sampajannam’, ’sato ca sampajano’, or ’sato sampajano’. As a result, it has been widely interpreted as an exhortation to be mindful, and has been defined as being nearly synonymous with sati (awareness), merely indicating a greater intensity of awareness. However, the texts of the Abhidhamma Pitaka suggest a different rendering of this word. In the Dhammasangani , Vibhanga and Dhatukhatha, we find the following definition:
“What is sampajanna? That which is wisdom, understanding, investigation, deep investigation, truth investigation, discernment, discrimination, differentiation, erudition, proficiency, skill, analysis, consideration, close examination, breadth, sagacity, guidance, insight, thorough understanding of impermanence… right view-this is called sampajanna.”
This plethora of nouns and metaphors clearly convey that sampajanna is not awareness but wisdom. This definition is confirmed by the etymology of the word, formed by the addition of the prefix ’sam’  to ‘pajanana’, ‘knowing with wisdom’. Rather it refers to an intensified kind of understanding–knowing correctly with wisdom or knowing in totality with thorough understanding. The exhortation of the Buddha is to develop not simply awareness but also wisdom.
This is why the text states:
‘Sampajannam ti panna. Sampajannam ti panna’, meaning ‘Sampajanna is wisdom’. 
The commentaries explain more precisely what sampajanna consists of: ‘Samma pakarehi aniccadini janati ti sampajannam’ , meaning:
‘One who knows impermanence in a right way (as well as suffering and egolessness), has wisdom, sampajanna.’
‘Samantato pakarehi pakattham va savisesam janati ti sampajano.’ , meaning, ‘One who understands the totality clearly with wisdom from all angles (of whatever is happening moment to moment), or who knows distinctly (the ultimate), has sampajanna.
The Buddha always taught that wisdom (panna) is knowing things from different angles in the correct way. He used these descriptions–samma pakarehi jananam (seeing from different perspective, in totality); samantato pakarehi-jananam (having a complete and correct picture, so that nothing is left unseen and unknown).
‘Samma, samantato, samanca pajananto sampajano’, meaning ‘One who knows in a right way in totality through one’s wisdom is sampajano.’
In particular, as meditators we must see not only the superficial, external appearances of things, that is, the apparent truth (sammuti saccasammuti sacca), but also the ultimate (paramattha saccaparamattha sacca) or subtle understanding of reality. The apparent truth about the world and ourselves is that we exist as individual separate entities, but the ultimate truth is that every moment, everything, both the world as well as ourselves, is in constant flux. This fact of impermanence has to be realised on the basis of experience, not merely at the intellectual level. It is only when we experience this reality of arising and passing away that we emerge from suffering (dukkha) and egotism (atta). This is what sampajanna enables us to do.
Therefore, for a meditator, sampajanna is complete understanding. It is insight into all aspects of the human phenomenon, mental as well as physical. One must understand that whenever the mind encounters an object, it perceives and evaluates it in a distorted way through the coloured lens of past conditioning; it therefore reacts with ignorance, craving or aversion. This is the process that produces suffering because wisdom is lacking.
Mind is reflected in the body and it is through its physical manifestation that we can clearly grasp its nature of arising and passing away. This is why we find in the Mahasatipatthana Sutta that the paragraph on sampajanna is contained in the section on the observation of body (kayanupassana). To realise the fact of impermanence of our bodily activities, we must experience them at the level of sensations (vedana) felt within the body. At a deep, intuitive level, these enable us to recognise our ephemeral nature.
Thus, sampajanna is the realisation of our own ephemeral nature at the deepest level. Far from being the equivalent of sati, it is the complement of sati. The uniting of these two faculties is satipatthana, the establishing of awareness, by means of which we can reach the goal of freedom from suffering.
Notes: (All references VRI edition)
For examples see Pali-English Dictionary, ed. T. W. Rhys Davids, Pali Text Society London, 1925, entries for sampajanna and sampajano
Dhammasangani, 1359; Vibhanga 360; Puggalapannatti, 80
See A Dictionary of the Pali Language, ed. R. C. Childers, Kegan Paul Ltd. London, 1909, p. 423, under entry for sam
pa + janana = pajanana-know with wisdom
Dhammasangani Atthakatha,16, Kamavacarakusalabhajamiyam; Patisambhidamagga Atthakatha, 1.1.108 - 9
Digha Nikaya Tika 2.373