1. Vedanā Vedanā :feeling or sensation.
Vedanā has a cognitive dimension which is conveyed by the word 'feeling' but not by 'sensation‘.
The word vedanā comes from root vid, which has a twofold meaning involving both knowledge and (mere) feelings: intellectually it means to know and experientially it means to feel.

2. “vedeti vedetīti kho āvuso, tasmā vedanā ti vuccati”, ““It feels, friend; therefore it is called feeling [vedanā].” [MN]
“What does it feel? It feels pleasant (sukha), painful (dukkha), and neither-painful-nor-pleasant (adukkhamasukha).
According to the dependent origination formula, feeling has contact as its condition and that feeling itself is therefore more than mere sensory event.

3. Feelings are experienced (vedayitaṃ) either bodily or mentally, making six types of feeling in all.
They can be experienced with regard to material (sāmisa) or non-material (nirāmisa) things.
Do feelings have both a physical and a mental aspect?
Feelings that have a tactile origin are experienced bodily (kāya is the object corresponding to the sense of touch) and feelings that have a non-tactile origin are experienced mentally

4. Six Kinds of Vedanā
Vedanā is six-fold which arise from contact with each of the six senses: feeling which arises through contact of eye…,
The arising of feeling is dependent on the presence of several factors: consciousness, at least one of the organs of sense, and contact between the organ and its corresponding external object of sense. The feeling is subsequently apperceived (or identified).
Visual awareness ('eye consciousness') (cakkhuviññāṇa) arises because of eye and [visible] forms; contact [is the] combination of the three; feelings are caused by the contact; that which one feels, one apperceives (or identifies).

5. The pleasant feelings we experience as a result of hearing or seeing something nice are not in this sense 'bodily' feelings.
Bodily pain is produced through bodily contact.
Mental pain arises through mental contact (manosamphassajaṃ)
All feelings do not have both a physical and a mental aspect.

6. Sāmisa and nirāmisa are used to make a distinction between the experience of feelings which arise from the sensory contact, and the experience of feelings which arise from levels of meditation.
Sāmisa refers to the five kāmaguṇa.

7. Two Kinds of Vedanā: bodily (kāyika) and mental (cetasika)
“Bodily feeling’ must refer to the source from which such feeling has arisen, namely the body, not to the nature of the feeling itself, which by definition has to be a mental phenomenon.”

8. Three Kinds of Vedanā: pleasant (sukha), painful (dukkha), and neither-painful-nor-pleasant (adukkhamasukha).
sukhā vedanā: Whatever is felt bodily or mentally as pleasing and pleasant.
dukkhā vedanā: Whatever is felt bodily or mentally as painful and unpleasant.
adukkhamasukā vedanā : Whatever is felt bodily or mentally as neither pleasant nor unpleasant.

9. Two kinds of sukha: Kāyikasukha: Any bodily well-being, bodily pleasure and pleasure felt as born of body contact, welcome, pleasant feeling born of body contact, is bodily pleasure.
Cetasikasukha: Any mental well-being, mental pleasure, well-being, and pleasure felt as born of mental contact, welcome pleasant feeling as born of mental contact, is mental pleasure.
Can we relate sukha-vedanā with the happiness of nibbāna?

10. Dukkhā Vedanā: dukkha is equally mental and physical.
Is adukkhamasukā vedanā physical or mental?
These threefold feelings are born of contact.

11. Then, having seen a form with the eye, a bhikkhu understands one that is a basis for equanimity (upekhāṭṭhāniya) thus: ‘Such it is!’ There is eye-consciousness, and in dependence on a contact to be experienced as neither-painful-nor-pleasant there arises a neither-painful-nor-pleasant feeling.

12. Adukkhamasukhā vedanā: It can be found on the “occasion of the disappearance of the unpleasant or pleasant feeling in a middle position between the two, as contrary to agreeable and the disagreeable [Edward Conze]
According to the Visuddhismagga, it is also called ‘equanimity’. It has the characteristic of experiencing what is contrary to both desirable and undesirable. Its function is neutral. Its manifestation is unevident. Its proximate cause should be understood as the cessation of pleasure (bliss).

13. Three aspects of contact: the pleasing (manāpa), the displeasing (amanāpa), and the indifferent (upekhāṭṭhāniya) …
“Having seen a form with the eye, a bhikkhu understands an agreeable (manāpa) one thus: ‘Such it is!’ There is eye-consciousness, and in dependence on a contact to be expe­rienced as pleasant there arises a pleasant feeling. Then, hav­ing seen a form with the eye, a bhikkhu understands a disagree­able (amanāpa) one thus: ‘Such it is!’ There is eye-consciousness, and in dependence on a contact to be experienced as painful there arises a painful feeling.

14. Five Kinds of Vedanā
Sukhindriyā (pleasure faculty): Whatever bodily pleasure there is, bodily comfort, the pleasant comfortable feeling born of body-contact.
It has the characteristic of experiencing a desirable tangible datum.

15. Dukkhindriyā (pain faculty): Whatever bodily pain there is, bodily unpleasant, the painful unpleasant feeling born of body-contact.
Yaṃ kho bhikkhave kāyikaṃ dukkhaṃ kāyikaṃ asātaṃ kāya-samphassajaṃ dukkhaṃ asātaṃ vedayitaṃ, idaṃ vuccati bhikkhave dukkhindriyaṃ.
Somanassindriyā (joy faculty): Whatever mental pleasure there is, mental pleasant, the pleasurable pleasant feeling born of mind-contact.

16. Domanassindriyā (displeasure faculty): Whatever mental pain there is, mental unpleasant, the painful unpleasant feeling born of mind-contact… .
Yaṃ kho bhikkhave cetasikaṃ dukkhaṃ cetasikaṃ asātaṃ manosamphassajaṃ dukkhaṃ asātaṃ vedayitaṃ, idaṃ vuccati bhikkhave domanassindriyaṃ
Upekkindriyā (equanimity faculty): Whatever feeling there is, whether bodily or mental, that is neither comfortable nor uncomfortable.

17. Two main meanings of upekkha: In relation to vedanā it refers to neutral vedanā.
As a mental quality, however, it refers to mental neutrality, impartiality, or balance of mind (tatramajjhattatā).
Upekkhā is thus often used in the Pāli texts to signify equanimity, the state of mind which is not swayed by craving or aversion.

18. Six Kinds of Vedanā
The six kinds are those which arise from contact with each of the six senses.
Cakkhusamphassajā Vedanā born of eye-contact
Sotasamphassajā Vedanā born of ear-contact
Ghānasamphassajā Vedanā born of nose-contact
Jivhāsamphassajā Vedanā born of born of taste-contact
Kāyasamphassajā Vedanā born of body-contact
Manosamphassajā Vedanā born of mind contact

19. The eighteen kinds are the six ways (presumably according to the senses) of paying attention to (upavicāra) joy, grief and indifference respectively.
The thirty-six feelings comprise a more complex analysis of feeling in that it relates the six forms of joy, grief and indifference (that is, each of them experienced according to the six senses) with the worldly life (gehasita) and with the renunciatory life (nekkhammasita) in turn."

20. According to the analysis into one hundred and eight feelings, the thirty-six feelings can be classified as past, present or future.
The distinctions 'worldly' and 'renunciatory‘ apply to the manner in which the feelings arise: whether they arise from the perception of material things, or whether they arise from the discernment of the transitory nature of things seen.

21. This reflects the distinction made between the ordinary (ignorant) man, the puthujjana, and the noble disciple of the Buddha's teaching, the ariyasāvaka.
The well-taught ariyasāvaka knows, for example, that there is a refuge from disagreeable feeling other than happiness through sense pleasures. He or she would, presumably, experience feelings as renunciatory.
This is also described as having feelings but being detached from them.

22. “Whatever is felt is included in suffering”
Yaṃ kiñci vedayitaṃ taṃ dukkhasmin ti
That has been stated with reference to the impermanence of formations … to formations being subject to destruction … to formations being subject to vanishing … to formations being subject to fading away … to formations being subject to cessation … to formations being subject to change.