There are moments when there are no sense-impressions, when one does not think, when there are no akusala cittas or kusala cittas. Is there at those moments still citta? Even when there are no sense-impressions and no thinking, there must be citta; otherwise there would be no life. The type of citta which
arises and falls away at those moments is called bhavanga-citta.  Bhavanga literally means 'factor of life'; bhavanga is usually translated into English as 'life-continuum'. The bhavanga-citta sees to it that there is continuity in a life-span, so that what we call a 'being' keeps alive.

One may wonder whether bhavanga-cittas often arise. There must be countless bhavanga-cittas arising at those moments when there are no sense-impressions, no thinking, no akusala cittas or kusala cittas. When we are asleep and dreaming there are akusala cittas or kusala cittas, but even when we are in a dreamless sleep, there still has to be citta. There are bhavanga-cittas at these moments. Also when we are awake  there are countless bhavanga-cittas arising; they arise in between the different processes of citta. It seems that hearing, for example, can arise very shortly after seeing, but in reality there are different processes of citta and in between these processes there are bhavanga-cittas.

The bhavanga-citta is the same type of citta as the first citta in life, the patisandhi-citta (rebirth-consciousness). When the patisandhi-citta falls away it conditions the next citta to arise which is the second citta in that life. This citta is the first bhavanga-citta in life.

The bhavanga-citta is vipakacitta; it is the result of the same kamma which produced the patisandhi-citta. There is only one patisandhi-citta in a life, but there are countless bhavanga-cittas. Not only the first bhavanga-citta, but all
bhavanga-cittas arising during a lifespan are the result of the kamma which produced the patisandhi-citta. 

There are nineteen types of patisandhi-citta and thus there are nineteen types of bhavanga-citta. If the patisandhi-citta is akusala vipaka, which is the case when there is birth in a woeful plane, all bhavanga-cittas of that life are akusala vipaka as well.  If the patisandhi-citta is ahetuka kusala vipaka, in which case one is handicapped from birth , all bhavanga-cittas of that life are ahetuka kusala vipaka as well. If the patisandhi-citta is sahetuka (arising with sobhana hetus or beautiful roots), the bhavanga-citta is sahetuka as well. All bhavanga-cittas during a lifespan are of the same type as the patisandhi-citta of that life. If one is born with two hetus, with alobha (non-attachment or generosity) and adosa (non-aversion or kindness), but without wisdom, then all bhavanga-cittas have only two hetus. Such a person can cultivate wisdom, but he cannot become enlightened during that life. If one is born with three hetus, which means that one is born with alobha, adosa and panna (wisdom), all bhavanga-cittas are accompanied by these three sobhana hetus (beautiful roots) as well. Thus that person is more inclined to cultivate wisdom and he can attain enlightenment during that life. If one is born with somanassa (happy feeling), all
bhavanga-cittas of that life are accompanied by somanassa.

Every citta must have an object and thus the bhavanga-citta too has an object. Seeing has what is visible as object; hearing has sound as object, but the bhavanga-citta has an object which is different from the objects presenting themselves through the senses and through the mind-door. The bhavang-acitta which is the same type of citta as the patisandhi-citta also experiences
the same object as the patisandhi-citta.
 

As we have seen (Ch. 10) the patisandhi-citta experiences the same object as the akusala cittas or kusala cittas arising shortly before the cuti-citta of the previous life. If akusala kamma is going to produce the patisandhi-citta, akusala cittas arise shortly before the cuti-citta and they experience an unpleasant object. If kusala kamma is going to produce the patisandhi-citta, kusala cittas arise
shortly before the cuti-citta and they experience a pleasant object.  Whatever the object is, the patisandhi-citta of the next life experiences the same object.

The patisandhi-citta is succeeded by the first bhavanga-citta of that life and this citta experiences the same object as the patisandhi-citta.  Moreover, all bhavanga-cittas of that life experience that object.

The 'Visuddhimagga' (XIV, 114) states with regard to the bhavanga-citta:

         When the patisandhi-citta has ceased, then, following
         on whatever kind of rebirth-consciousness it may be, the
         same kinds, being the result of the same kamma whatever
         it may be, occur as bhavanga-cittas with that same object;
         and again those same kinds. And as long as there is no
         other kind of arising of consciousness to interrupt the
         continuity they also go on occurring endlessly in periods
         of dreamless sleep, etc., like the current of a river.

The bhavanga-cittas are like the current of a river and this is interrupted when there is an object presenting itself through one of the senses or through the mind-door. When the cittas of the sense-door process or the mind-door process have fallen away, there is again the current of bhavanga-cittas.
 

When an object contacts one of the five senses the stream of bhavanga-citta is interrupted and there is a sense-impression.  However, there cannot be a sense-impression immediately.  When sound, for example, impinges on the ear-sense, there is not hearing immediately. There are still some bhavanga-cittas
arising and falling away before the panca-dvaravajjana-citta (five-sense-door-adverting-consciousness) adverts to the sound through the ear-door and hearing arises. The bhavanga-cittas do not perform the function of adverting to the sound which contacts the ear-sense, they do not experience the sound. They have their own function which is keeping the continuity in a
lifespan, and they experience their own object which is the same as the object of the patisandhi-citta. Although the bhavanga-citta does not experience the sound which contacts the ear-sense, it can be affected, 'disturbed' by it and then the stream of bhavanga-cittas will be interrupted and sound will be experienced
by cittas which arise in the ear-door process.

When a rupa impinges on one of the senses bhavanga-cittas can be affected by it. First there is one moment of bhavanga-citta arising and falling away which is denoted by the name 'atita-bhavanga' or 'past bhavanga'. Then it is succeeded by
the 'bhavanga calana' or 'vibrating bhavanga'. It is called vibrating since it is disturbed by the object, although it does not experience it. The last bhavanga-citta of the stream of bhavanga-cittas and before the panca-dvaravajjana-citta adverts to the object is the bhavangupaccheda or 'arrest bhavanga'.

The different names which denote these bhavanga-cittas do not represent different functions; bhavanga-cittas have as their only function to keep the continuity in the life of a being. The different names point only to the fact that these bhavanga-cittas are the last ones when the stream is interrupted and a new object is experienced by a process of cittas. When the sense-door process is over, the stream of bhavanga-cittas is resumed, so that the series of cittas succeeding one another in our life is not interrupted.

The object which impinged on one of the senses is then experienced through the mind-door. In between the sense-door process and the mind-door process, however, there are bhavanga-cittas.  When the cittas of the mind-door process have fallen  away, the stream of bhavanga-cittas is resumed.

An object which is experienced through one of the five senses is rupa. Rupa arises and falls away, but it does not fall away as rapidly as nama. One rupa can be experienced by several cittas succeeding one another in a process. When, for
example,  the rupa which is sound impinges on the ear-sense it can be experienced by cittas arising in the ear-door process.  Before the process starts there are bhavanga-cittas. The last bhavanga  which arise before the sound can be experienced by the cittas of the ear-door process are : atita-bhavanga (past
bhavanga),   bhavanga-calana  (vibrating bhavanga), bhavangupaccheda  (arrest-bhavanga).

When the stream of bhavanga-cittas has been arrested, the ear-door-adverting-consciousness    (sota-dvaravajjana-citta) adverts to the object through the ear-door. This citta can be followed  by other cittas which each perform their own function in that process before it falls away. Rupa lasts as long as seventeen moments of citta counting from the atita-bhavanga, the past bhavanga, there can be seventeen moments of citta succeeding one another if the sense-door process runs its full course. If the rupa which will be object has contacted more than one atita bhavanga,  it will have fallen away before the process can be completed, since it cannot last longer than seventeen moment of citta. A process can, after it has started, be interrupted,  for example, after the votthapana-citta, before kusala cittas or akusala cittas can arise. It may also happen that the atita-bhavanga  is succeeded by the bhavanga-calana, but that
the bhavangupaccheda does not arise; then there will be no process of cittas. Sound may, for example, impinge on the ear-sense and then the atita-bhavanga which arises is succeeded by the bhavanga-calana. However, the bhavangupaccheda does not arise and thus the stream of bhavanga-cittas is not interrupted and the ear-door process cannot start. In that case the sound
cannot be heard.

When a sense-door process of cittas begins, the rupa which has impinged on that sense-door is experienced and when the last citta of that process has fallen away there are bhavanga-cittas again. The object, however, can be experienced through the mind-door. The last two bhavanga-cittas arising before the
mind-door-adverting-consciousness (mano-dvaravajjana-citta) are the bhavanga-calana (vibrating bhavanga) and the bhavangupaccheda (arrest-bhavanga) . Then the mano-dvaravajjana-citta adverts to the object through the mind-door and it is succeeded by seven kusala cittas or akusala
cittas (in the case of non-arahats). Summarizing these cittas, they are :

bhavanga-calana (vibrating bhavanga)
bhavangupaccheda (arrest-bhavanga)
mano-dvaravajjana-citta (mind-door-adverting-consciousness)
seven akusala or kusala cittas (or, for the arahat, kiriyacittas)

Before the arising of the bhavanga-calana of that mind-door process there are many bhavanga-cittas arising and falling away. There is no atita-bhavanga, past bhavanga, before the mind-door process.

When the mind-door process is over, the stream of bhavanga-cittas is resumed until there is again a process of cittas experiencing an object through one of the sense-doors or through the mind-door. There are countless bhavanga-cittas
arising all through our life in between the processes of cittas experiencing an object through one of the sense-doors or through the mind-door.

What is the mind-door? It is different from the sense-doors. The sense-doors are the following rupas: eye-sense, ear-sense, smelling-sense, tasting-sense and body-sense. Body-sense is all over the body. The mind-door is not one of these rupas. One may wonder whether the mind-door is nama or rupa. We should
consider how the first citta of the mind-door process adverts to the object. The first citta of the mind-door process which adverts to the object is the mano-dvaravajjana-citta. This citta does not advert to the object through one of the five senses. Therefore, the mind-door must be nama; it is a citta. The citta which precedes the mano-dvaravajjana-citta is the bhavangupaccheda-citta (arrest-bhavanga). The bhavangupaccheda-citta is the mind-door through which the mano-dvaravajjana-citta adverts to the object.

The study of the different sense-door processes and mind-door processes which take their course according to conditions will help us to see realities as elements which are beyond control, devoid of self. We may, for example, be infatuated by a beautiful sound we hear. What we take for a long moment of hearing are many different moments which do not stay. Even when we do not know yet what kind of sound it is, sound has already been experienced through the mind-door
since cittas succeed one another extremely rapidly, arising and falling away. Neither does sound stay, it falls away.

We read in the 'Kindred Sayings' (IV, Salayatana-vagga, Kindred Sayings on Sense, Fourth Fifty, Ch.IV, par. 205, The Lute) that the Buddha said to the monks:

‘…Suppose, monks, the sound of a lute has never been heard by a rajah or royal minister. Then he hears the sound of a lute and says: 'Good man, pray, what is that sound so entrancing, so delightful, so intoxicating, so ravishing, of such power to bind?'

Then they say to him : 'That, lord, is the sound of what is called a lute, that sound so entrancing, so delightful, so intoxicating, so ravishing, of such power to bind.'

Then he says: 'Go, my man. Fetch me that lute.'

So they fetch him that lute and say to him : 'This, lord, is that lute, the sound of which is so entrancing... of such power to bind.'

Then he says: 'Enough of this lute, my man. Fetch me that sound.'

They say to him: 'This lute so called, lord, consists
 of divers parts, a great number of parts. It speaks because
 it is compounded of divers parts, to wit, owing to the
 belly, owing to the parchment, the handle, the frame,
 the strings, owing to the bridge and proper effort of a
 player. Thus, lord, this lute, so called, consists of divers
 parts, of great number of parts. It speaks because it is
 compounded of divers parts.'

Then that rajah breaks up that lute into ten or a
hundred pieces. Having done so, he splinters and splinters
it again. Having done so, he burns it in fire, then makes
it a heap of ashes and winnows the heap of ashes in a
strong wind or lets them be borne down by the swift
stream of a river.

Then he says: 'A poor thing is what you call a lute,  a lute, my men, whatever a lute may be. Herein the world is exceeding careless and led astray.'

Even so, monks, a monk investigating body as far as there is scope for body, investigating feeling, perception, the activities (sankharakkhandha), investigating consciousness, so far as there is scope for consciousness, - -in all of these investigations, whatever there be of 'I' or 'I am' or 'Mine', there is none of that for him'.

1.  At which moments do bhavanga-cittas arise?
2.  When did the first bhavanga-citta in life arise?
3.  Can bhavanga-citta be ahetuka?
4.  Can bhavanga-citta be accompanied by wisdom?