There are eighteen types of ahetuka citta, or cittas arising without hetu (root). Fifteen types of ahetuka citta are vipaka. As we have seen, ten of these fifteen cittas are dvi-panca vinnanas. They are: 

                 two seeing-consciousness 
                 two hearing-consciousness 
                 two smelling-consciousness 
                 two tasting-consciousness 
                 two body-consciousness 

Seeing-consciousness is the result of kamma. When it is the result of an ill deed, seeing-consciousness is akusala vipakacitta which experiences an unpleasant object; when it is the result of a good deed, it is kusala vipakacitta which experiences a pleasant object. The function of seeing consciousness is to experience visible object. 

 Kamma which produces seeing-consciousness does not only produce the vipakacitta which is seeing-consciousness, it also produces two other kinds of vipakacitta, which succeed seeing-consciousness. Seeing-consciousness is succeeded by vipakacitta which receives the object. This citta, which is called sampaticchana-citta (receiving-consciousness). Visible object which is experienced by seeing-consciousness does not fall away when seeing-consciousness falls away, because it is rupa; rupa does not fall away as rapidly as nama. When an object is experienced through one of the six doors, there is not merely one citta experiencing that object, but there is a series of cittas succeeding one another, which share the same object. 

 If the seeing-consciousness is akusala vipaka, the sampaticchana-citta (receiving-consciousness) is also akusala vipaka; if the seeing-consciousness is kusala vipaka, the sampaticchana-citta is also kusala vipaka. Thus there are two types of sampaticchana-citta: one is akusala vipaka and one is kusala vipaka. Sampaticchana-citta: is ahetuka vipaka; there are no akusala hetus (unwholesome roots) or sobhana hetus (beautiful roots) arising with this type of
citta. Sampaticchana-citta succeeds seeing-consciousness; seeing-consciousness
is a condition for the arising of sampaticchana-citta. Likewise, when there is a process of cittas experiencing sound, sampaticchana-citta succeeds hearing-consciousness. It is the same with regard to nose, tongue, and body. 

Sampaticchana-citta always arises with upekkha (indifferent feeling), no matter whether the sampaticchana-citta is akusala vipaka or kusala vipaka. 

After the sampaticchana-citta has arisen and fallen away,  the process of cittas is not yet over. The sampaticchana-citta is succeeded by another ahetuka vipakacitta which is still the result of kamma. This type of citta is called santirana-citta (investigating-consciousness). Santirana-citta investigates or considers the object which was 'received' by the sampaticchana-citta. Santirana-citta succeeds sampaticchana-citta through five sense-doors; sampaticchana-citta is a condition for the arising of santirana-citta. When seeing has arisen, sampaticchana-citta succeeds the seeing-consciousness, and santirana-citta succeeds the sampaticchana-citta in the process of cittas which experience visible object through eye-door. It is the same with the santirana-citta which arises in the process of cittas experiencing an object through ear-door, nose-door, tongue-door, body-door. It succeeds the sampaticchana-citta. We cannot choose whether santirana-citta should arise or not; cittas arise because of conditions, they are beyond control. 

Santirana-citta is also an ahetuka vipakacitta. When the object is unpleasant (anittharammana), the santirana-citta is akusala vipaka and it is accompanied by
upekkha (indifferent feeling). As regards santirana-citta which is kusala vipaka,
there are two kinds. When the object is pleasant (ittharammana), but not
extraordinarily pleasant, santirana-citta is accompanied by upekkha. When the
object is extraordinarily pleasant (atittharammana), the santirana-citta is
accompanied by somanassa. Thus, there are three kinds of santirana-citta in all. It depends on conditions which kind of santirana-citta arises. 

Thus, there are fifteen types of ahetuka citta which are vipaka. Summarizing
them, they are: 

                 10  cittas which are dvi-panca-vinnana (five pairs) 
                   1  sampaticchana-citta (receiving-consciousness) which is 
                       akusala vipaka 
                   1  sampaticchana-citta which is kusala vipaka 
                   1  santirana-citta (investigating-consciousness) which is 
                       akusala vipaka, accompanied by upekkha 
                   1  santirana-citta which is kusala vipaka, accompanied by 
                       upekkha 
                   1  santirana-citta which is kusala vipaka, accompanied by 
                       somanassa 

Seven types of the ahetuka vipakacittas are akusala vipaka and eight types are
kusala vipaka, since there are two types of santirana-citta which are kusala vipaka.

As we have seen, there are altogether eighteen ahetuka cittas. Of these eighteen
ahetuka cittas fifteen are vipakacittas and three are kiriyacittas. Kiriyacittas are
different from akusala cittas and kusala cittas and from vipakacittas. Akusala
cittas and kusala cittas are cittas which are cause; they can motivate ill deeds and
good deeds which are capable of producing their appropriate results. Vipaka-cittas are cittas which are the result of akusala kamma and kusala kamma. Kiriyacittas are cittas which are neither cause nor result. 

One type of ahetuka kiriyacitta is the 'five-door-adverting-consciousness', in Pali: panca-dvaravajjana-citta. ('Panca' is five, 'dvara' is door, 'avajjana' is adverting or turning towards.’) When an object impinges on one of the five senses, there has to be a citta which adverts or turns towards the object through that sense-door. When visible object impinges on the eye-sense, there has to be the adverting-consciousness which adverts towards visible object through the
eye-door, or cakkhu-dvaravajjana-citta (eye-door-adverting-consciousness),
before there can be seeing-consciousness (cakkhu-vinnana). When sound
impinges on the ear-sense, the ear-door-adverting-consciousness (sota-dvaravajjana-citta) has to advert to the sound through the ear-door before there can be hearing-consciousness (sota-vinnana). The panca-dvaravajjana-citta merely turns towards the object which impinges on one
of the five sense-doors. But it does not see or hear. The panca-dvaravajjana-citta
is an ahetuka kiriyacitta, it arises without hetu (root); there is not yet like or dislike. The panca-dvaravajjana-citta is succeeded by one of the dvi-panca-vinnanas (five pairs), which is vipakacitta. 

Each citta which arises in the process of cittas experiencing an object has its own
function. 

The cittas which experience an object through one of the senses do not know
anything else but that object. When one, for example, is reading, the citta which
sees experience only visible object and it does not know the meaning of the
letters. After the eye-door process has been completed visible object is
experienced through the mind-door and then there can be other mind-door
processes of cittas which know the meaning of what has been written and which
think about it. Thus, there are processes of cittas which experience an object
through one of the senses and processes of cittas which experience an object
through the mind-door. 

Another type of ahetuka kiriyacitta is the mano-dvaravajjana-citta (mind-door-adverting-consciousness), which arises both in the sense-door
process and in the mind-door process but performs two different functions
according as it arises in each of those two kinds of processes. When an object
contacts one of the sense-doors, the panca-dvaravajjana-citta (five-door-adverting-consciousness) turns towards the object, one of the dvi-panca-vinananas experiences it, sampaticchana-citta receives the object and
santirana-citta investigates it. The santirana-citta is succeeded by an ahetuka
kiriyacitta which experiences the object through that sense-door and 'determines' (votthapana) the object. It is actually the same type of citta as the mano-dvara vajjana-citta, (mind-door-adverting-consciousness, the first citta of the mind-door process), but when it arises in the sense-door process it can be called votthapana-citta, since it performs the function of determining the object in the sense-door process. The votthapana-citta, after it has determined the object, is, on the case of non-arahats, followed by akusala cittas or by kusala cittas. It depends on one's accumulations of akusala and kusala whether the votthapana citta will be succeeded by akusala cittas or by kusala cittas. 

After the cittas of the sense-door process have fallen away the object can be
experienced through the mind-door. The mano-dvaravajjana-citta is the first citta of the mind-door process which experiences that object which has fallen away already. In the sense-door process the panca-dvara vajjana-citta adverts to the object which has not fallen away yet. For example, it adverts to visible object or sound which is still impinging on the appropriate sense-door. The mano-dvaravajjana-citta which arises in the mind-door process however, can
experience an object which has fallen away already. After the
mano-dvaravajjana-citta has adverted to the object it is succeeded by either kusala cittas or akusala cittas (in the case of non-arahats), which experience that same object. The mano-dvaravajjana-citta itself is neither akusala citta nor kusala citta; it is kiriyacitta. 

Although the votthapana-citta in the sense-door process and the
mano-dvaravajjana-citta in the mind-door process are the same type of citta, an
ahetuka kiriyacitta, their functions are different. In the sense-door process this
citta performs the function of votthapana (determining the object) and in the
mind-door process it performs the function of avajjana (adverting). Thus,
whenever we deal with the mano-dvaravajjana-citta we have to know what
function it is performing. 

When sound impinges on the earsense it can be experienced by cittas arising in
the ear-door process and after that it is experienced by cittas arising in a
mind-door process. Processes of cittas which experience in object through one of
the five senses and through the mind-door succeed one another time and again. 

How can there be akusala cittas or kusala cittas in the process of cittas which
experience an object through one of the sense-doors, when one does not even
know yet what it is that is experienced? There can be akusala cittas or kusala cittas before one knows what it is. One can compare this situation with the case of a child who likes a brightly coloured object such as a balloon before it knows that the object is a balloon. We can have like or dislike of an object before we know what it is. 

Another ahetuka kiriyacitta is the hasituppada-citta
(smile-producing-consciousness). Only arahats have this kind of citta. Laughing
and smiling can be motivated by different kinds of cittas. When people who are
not arahats smile, it is usually motivated by lobha or by kusala citta. Arahats do
not have any defilements; they do not have akusala cittas. Neither do they have
kusala cittas; they do not accumulate any more kamma. Instead of kusala cittas
they have kiriyacittas, accompanied by sobhana (beautiful) roots, sobhana
kiriyacittas. Arahats do not laugh aloud, because they have no accumulations for
laughing; they only smile. When they smile the smiling may be motivated by
sobhana kiriyacitta or by the ahetuka kiriyacitta which is called hasituppada-citta. 

Thus, of the eighteen ahetuka cittas, fifteen are vipakacittas and three are
kiriyacittas. The ahetuka kiriyacittas are: 

                 1. Panca-dvaravajjana-citta (five-door-adverting 
                     consciousness) 
                 2. Mano-dvaravajjana-citta (mind-door-adverting- 
                     consciousness), which performs the function of 
                     adverting to the object through the mind-door 
                     when it arises in the mind-door process and 
                     which performs the function of votthapana 
                     (determining the object) when it arises in the 
                     sense-door process 
                 3. Hasituppada-citta (smile-producing-consciousness) 

Those who are not arahats can have only seventeen of the eighteen ahetuka cittas. These seventeen types of ahetuka citta arise in our daily life. When an object impinges on one of  the five senses, panca-dvaravajjana-citta (five-door-adverting consciousness) turns towards the object through that sense-door. This citta is followed by panca-vinnana which experiences the object, by sampaticchana-citta which receives it, by santirana-citta which investigates it and by votthapana-citta which determines the object and then by akusala cittas or kusala cittas. When the cittas of the sense-door process have fallen away the object is experienced through the mind-door. The mano-dvaravajjana-citta adverts to the object through the mind-door and is then followed by akusala cittas or kusala cittas. There is 'unwise attention' (ayoniso manasikara) to the object which is experienced if akusala cittas arise, and there is 'wise attention' (yoniso manasikara) to the object if kusala cittas arise. For example, when we see insects there may be dosa-mula-cittas (cittas rooted in aversion). Thus, there is ayoniso manasikara (unwise attention). The dosa may be so strong that one wants to kill the insects; then there is akusala kamma. If one realizes that killing is akusala and one abstains from killing, there are kusala cittas and thus there is yoniso manasikara (wise attention). If one studies Dhamma and develops vipassana (insight) it is a condition for yoniso manasikara. When we are mindful of the nama or rupa which appears through one of the six doors, there is yoniso manasikara at that moment. 

When there are two people in the same situation, one person may have ayoniso
manasikara and the other may have yoniso manasikara. This depends on their
accumulations. We read in the 'Kindred Sayings' (lV, Salayatanavagga, Kindred
Sayings on Sense, Fourth Fifty, Ch.V, par. 202, Lustful) about the monk who,
after he has experienced an object through one of the six doors, has ayoniso
manasikara, and about the monk who has yoniso manasikara. We read that
Maha-Moggalla-na said to the monks: 

                 Friends, I will teach you the way of lusting and also 
                 of not lusting.... 

                 And how, friends, is one lustful? 

                 Herein, friends, a monk, seeing object with the eye, 
                 feels attachment for objects that charm, feels aversion 
                 from objects that displease, abides without mindfulness 
                 of the body, and his thoughts are mean. He realizes 
                 not, in its true nature, that emancipation of heart, 
                 that emancipation of wisdom, wherein those evil, 
                 unprofitable states that have arisen cease without 
                 remainder. 

                 This monk, friends, is called 'lustful after objects 
                 cognizable by the eye, nose, tongue…objects cognizable 
                 by the mind’ When a monk so abides, friends, if Mara 
                 come upon him by way of the eye, Mara gets an 
                 opportunity. If Mara come upon him....by way of the 
                 mind, Mara gets access, gets opportunity.... 

                 So dwelling, friends, objects overcome a monk, a 
                 monk overcomes not objects. Sounds overcome a monk, 
                 a monk overcomes not sounds. Scents, savours, 
                 tangibles and mind-states overcome a monk, a monk 
                 overcomes not sounds, scents, savours, tangibles and 
                 mind-states. This monk, friends, is called 'conquered 
                 by objects, sounds, scents, savours, tangibles and 
                 mind-states, not conquerer of them.’ Evil, unprofitable 
                 states, passion-fraught, leading to rebirth overcome him, 
                 states unhappy, whose fruit is pain, whose future is 
                 rebirth, decay and death. Thus, friends, one is lustful. 

                 And how, friends, is one free from lust? 

                 Herein, friends, a monk, seeing an object with the 
                 eye, is not attached to objects that charm, nor averse 
                 from objects that displease.... 

                 Tasting a savour with the tongue...with mind cognizing 
                 a mind-state, he is not attached to mind-states that 
                 charm, nor is he averse from mind-states that displease, 
                 but dwells with mindfulness of the body, his thought 
                 is boundless. So that he realizes in its true nature that 
                 emancipation of heart, that emancipation of wisdom, 
                 wherein those evil, unprofitable states that have arisen 
                 come to cease without remainder. 

                 This monk, friends, is called 'not lustful after 
                 objects cognizable by the eye... not lustful after 
                 mind-states cognizable by mind.' Thus dwelling, friends, 
                 if Mara come upon him by way of the eye, of the 
                 tongue,... of the mind, Mara gets no access, gets no 
                 opportunity.... 

                 Moreover, friends, so dwelling a monk conquers 
                 objects, objects do not conquer him. He conquers 
                 sounds, scents, savours, tangibles, mind-states. They 
                 do not conquer him. Such a monk, friends, is called, 
                 'conquerer of objects, sounds, scents, savours, tangibles 
                 and mind-states,’ He is conquerer, not conquered. He 
                 conquers those evil, unprofitable states, passion-fraught, 
                 inciting to lust, leading to rebirth, states unhappy, whose 
                 fruit is pain, rebirth, decay and death. Thus, friends, 
                 is one free from lust. 

1.  What is kiriyacitta? 
2.  When we smile, is it always motivated by lobha? 
3.  Can akusala cittas and kusala cittas and arise in a sense-door process?