For those who are interested, here is an extract from a post on sankhara.
Sankhāra – What It Really Means
1. Sankhāra is conventionally translated as “formations” and “mental formations”. Certainly the latter is a better translation. But it is much better to grasp the idea of sankhāra and just use that word. I recommend the same for most key Pāli words like saññā and viññāna.
It comes from “san” + “kāra” or actions that involve “san“; see, “What is “San”? Meaning of Sansāra (or Samsāra)“.
Therefore, “san” is associated with anything that is associated with the world of 31 realms. They are responsible for a wide variety of effects ranging from giving rise to future births (as in abhisankhāra) to just getting things done to living the current life.
2. Let us look at some example now.
Thinking about going to the bathroom is a sankhāra (kammically neutral). One gets the body to move to the bathroom using kāya sankhāra.
Thinking about killing a human being and carrying it out is a sankhāra with high kammic consequences or an abhisankhāra. It can lead to a birth in the apayas, and is an apunna abhisankhāra (or apunnābhisankhāra).
On the other hand, punna abhisankhāra (or punnābhisankhāra) have good kammic consequences and can lead to “good births”. Even more importantly, they are essential for making progress on the Path.
Good or bad kammā are done via those types of sankhāra. They can bring results (kamma vipāka) immediately, in this life, or in future lives. However, not all kammā lead to kamma vipāka; see, “What is Kamma? – Is Everything Determined by Kamma?“.
3. However, the word sankhāra is commonly used to indicate those with kammic consequences, as in “avijjā paccayā sankhāra“, where it really means, “avijjā paccayā apunnābhi sankhāra” or “avijjā paccayā punnābhi sankhāra“.
Here abhi sankhāra means “strong sankhāra”, and the word apunnābhi comes from “apunna” + “abhi“, which combine to rhyme as apunnābhi. Here “apunna” means “bad” or “immoral”.Thus,apunnābhi sankhāra means strong immoral sankhāra.
In the same way, punna + abhi + sankhāra becomes punnābhi sankhāra (for strong good sankhāra).
So, one really needs to pay attention to exactly what meaning need to be taken in a given case.
4. All our thoughts, speech, and bodily actions are based on sankhāra that arise in the mind. Therefore, it is important to realize that vaci sankhāra and kāya sankhāra also arise in the mind.
Kāya sankhāra are in “conscious thoughts” that make our bodies move. Killing, stealing, and sexual misconduct are due to apunnābhi kāya sankhāra.
Vaci sankhāra are in “conscious thoughts that we silently generate” and also those thoughts that lead to speech by moving the lips, tongue etc. Hate speech is due to apunnābhi vaci sankhāra. Thinking about a Dhamma concept is a punnābhi vaci sankhāra; see, “Correct Meaning of Vacī Sankhāra“.
On the other hand, manō sankhāra are in “unconscious thoughts” that arise automatically. We are not aware when they arise. They arise due to our gathi and can indicate our level of moha or avijjā. Since they arise unconsciously, manō sankhāra are unlikely to be abhisankhāra that have strong kammic consequences.
The fact that cetana plays a key role is clear when we look at the following definitions: “kāya sancetanā kāya sankhāra“, “vaci sancetanā vaci sankhāra“, and “manō sancetanā manō sankhāra“.
5. Let us take some examples to illustrate these three types of sankhāra.
In order to move the physical body, the mind must first generate thoughts about moving the body. Then that thought is executed with the help of the brain that sends necessary signals to the leg muscles, say, to move the legs.'
So, those kāya sankhāra are responsible for moving the legs. Now, if the purpose to move the body was to go somewhere to commit a bad deed, then it becomes an apunna abhisankhāra. These thoughts would have asōbhana cetasika (like greed or hate) in them.
If the purpose was to go somewhere to do a good deed, then it would become a punnābhi sankhāra. These thoughts would have sōbhana cetasika (like faith and compassion) in them.
If the purpose was to go the bathroom (kammically neutral), then it would be just a kāya sankhāra, not an abhisankhāra. In fact, breathing involves moving body parts (lungs), which is done without conscious thinking, but they are kāya sankhāra too. Those thoughts would not have sōbhana or asōbhana cetasika in them.
This is why the kammic nature of an act is decided by the intention that is in the mind, i.e., type of cetasika that arise with those thoughts.
6. Now, if person X gets angry at another person, X may not move any body parts, but may be generating very bad thoughts (saying to himself “I wish I could hit this person right now”); those are vaci sankhāra. This is explained in “Correct Meaning of Vacī Sankhāra“.
When those vaci sankhāra get strong, one may actually say those words out; then kāya sankhāra are also generated to move the mouth, lips, etc. They are still called vaci sankhāra.
Whether one is just talking to oneself or actually speaks out such bad words, they are both apunna abhisankhāra.
Of course vaci sankhāra can be punna abhisankhāra too. Person X watching a good deed by person Y, may be generating good thoughts about Y; those are punna vaci sankhāra.
Those also will be distinguished by the type of cetasika as in kāya sankhāra above.
7. Whether they are vaci or kāya sankhāra, if they have asōbhana cetasika in them, they have the tendency to “heat up” or “stress” the mind (Pali word is “thāpa“).
On the other hand, if sōbhana cetasika arise as vaci or kāya sankhāra, they have the tendency to “cool” a mind.
In the earlier post, “What Are Kilesa (Mental Impurities)? – Connection to Cetasika “, it was discussed in detail why understanding this fact is the pre-requisite for the Satipattana bhavana; see, “Satipattana Sutta – Relevance to Suffering in This Life“.
Just by comprehending this fact, one can start cultivating niramisa sukha, i.e. "cooling the mind" (this is early stage of Nibbana).
8. All other thoughts that arise in the mind without conscious thinking are manō sankhāra.
For example, when one gets hit by a cane, say, one feels the pain associated with it, and one realizes that the pain was caused by another person hitting with a cane. So, the manō sankhāra that are involved at the beginning have two cetasika of saññā (recognition of what happened) and vēdanā (pain caused). Another way to say it: manō sankhāra are involved in the vipāka stage.
However, based on that “sense input” of getting hit, now one could start generating vaci sankhāra and even kāya sankhāra. Those vaci sankhāra may involve just generating bad thoughts about that person (talking to oneself) or actually saying bad things to him. If the pain was strong, one may start generating bad kāya sankhāra and hit that person.
9. So, it is important to realize that whether one is just thinking (manō sankhāra and early stages of vaci sankhāra), or speaking out (vaci and kāya sankhāra), or using the body movements (kāya sankhāra), they all involve thoughts (citta).
Those thoughts arise in the mind, and become the commands to the brain to carry out the tasks of speaking and body movement.
10. The initial manō sankhāra is triggered by a kamma vipāka and are automatically generated in the mind due to one’s gati. Then subsequent vaci and kāya sankhāra are generated and we do have control over those; see, for example, “Correct Meaning of Vacī Sankhāra“.
So, the seeds for thinking, speaking, and acting start at the instant of the first sense input, say, seeing something or hearing something that gets one’s attention.
If the sense input is strong (and one gets interested in it via like or dislike), one will start many such citta vithi in a short time, and generate corresponding vaci and kāya sankhāra to “talk to oneself”, speak out, or to do bodily actions.
11. Without getting into details, conscious thinking that could lead to speaking and bodily actions occur in the seven javana citta in a citta vithi.
Vaci or kāya sankhāra arise due to many citta vithi running one after another. As we discussed previously, billions of citta vithi can run in a second. As the Buddha said, "mind is the fastest thing in this world".
Another key point is that the javana citta in subsequent citta vithi get stronger and stronger. This is why when we start thinking about a person that we really like or really dislike, we can keep generating increasingly stronger feelings about the situation.
Sometimes, we can see people getting angry by the minute. They are generating a lot of vaci sankhāra even without getting a word out. But one can see the person getting highly agitated: the face gets red and facial expression can show how angry he/she has become.
12. Therefore, even if we may start generating vaci and kāya sankhāra, we may not become aware of it for a short time. If one gets really angry one may lose control and may not even realize that one is getting into a bad situation.
“Catching oneself early” in the process of becoming angry is the key to control anger management. When one understands how this process happens and that it can escalate quickly into a bad situation, one can make a determination to catch it earlier next time.
We can prevent a lot of suffering in this life by catching such vaci and kāya sankhāra early.
As we discussed in the desana in the post,”Satipattana Sutta – Relevance to Suffering in This Life“, this is the key to anapana and satipattana bhavana.