Vedanā
Vedanā (Pāli and Sanskrit: वेदना) is an ancient term traditionally translated as either "feeling" or "sensation." In general, "vedanā" refers to the pleasant, unpleasant and neutral sensations that occur when our internal sense organs come into contact with external sense objects and the associated consciousness. Vedanā is identified as valence or "hedonic tone" in psychology. Vedanā is identified within the Buddhist teaching as follows: In the context of the twelve links, craving for and attachment to vedanā leads to suffering; reciprocally, concentrated awareness and clear comprehension of vedanā can lead to Enlightenment and the extinction of the causes of  suffering. Definitions. Theravada. Bhikkhu Bodhi states: Nina van Gorkom states: Mahayana. The Abhidharma-samuccaya states: Mipham Rinpoche states: Alexander Berzin describes this mental factors as "feeling (tshor-ba, Skt. vedanā) some level of happiness". He states: Relation to "emotions". Vedanā is the distinct valence or "hedonic tone" of emotional psychology, neurologically identified and isolated. Contemporary teachers Bhikkhu Bodhi and Chögyam Trungpa Rinpoche clarify the relationship between "vedanā" (often translated as "feelings") and Western notions of "emotions." Bhikkhu Bodhi writes: Chögyam Trungpa Rinpoche writes: Attributes. In general, the Pali canon describes vedanā in terms of three "modes" and six "classes." Some  discourses discuss alternate enumerations including up to 108 kinds. Three modes, six classes. Throughout canonical discourses ("Sutta Pitaka"), the Buddha teaches that there are three modes of vedanā: Elsewhere in the Pali canon it is stated that there are six classes of vedanā, corresponding to sensations arising from contact (Skt: "sparśa"; Pali: "phassa") between an internal sense organ ("āyatana"; that is, the eye, ear, nose, tongue, body or mind), an external sense object and the associated consciousness (Skt.: "vijnana"; Pali: "viññāna"). (See Figure 1.) In other words: Two, three, five, six, 18, 36, 108 kinds. In a few discourses, a  multitude of kinds of vedana are alluded to ranging from two to 108, as follows: In the wider Pali literature, of the above enumerations, the post-canonical Visuddhimagga highlights the five types of vedanā: physical pleasure ("sukha"); physical displeasure ("dukkha"); mental happiness ("somanassa"); mental unhappiness ("domanassa"); and, equanimity ("upekkhā"). Canonical frameworks. Vedanā is a pivotal phenomenon in the following frequently identified frameworks of the Pali canon: Mental aggregate. Vedanā is one of the five aggregates (Skt.: "skandha"; Pali: "khandha") of clinging (Skt., Pali: "upādāna"; see Figure 2 to the right). In the canon, as indicated above, feeling arises from the  contact of a sense organ, sense object and consciousness. Central condition. In the Chain of Conditioned Arising (Skt: "pratītyasamutpāda"; Pali: ""), the Buddha explains that: In the post-canonical 5th-century Visuddhimagga, feeling ("vedana") is identified as "simultaneously" and "inseparably" arising from consciousness ("viññāṇa") and the mind-and-body ("nāmarūpa"). On the other hand, while this text identifies feeling as "decisive" to craving and its mental sequelae leading to suffering, the conditional relationship between feeling and craving is not identified as simultaneous nor as being karmically necessary. Mindfulness base. Throughout the canon, there are references to the four "foundations of mindfulness  (satipaṭṭhāna"): the body ("kāya"), feelings ("vedanā"), mind states ("citta") and mental experiences ("dhammā"). These four foundations are recognized among the seven sets of qualities conducive to enlightenment ("bodhipakkhiyādhammā"). The use of "vedanā" and the other "satipaṭṭhāna" in Buddhist meditation practices can be found in the Satipaṭṭhāna Sutta and the Ānāpānasati Sutta. Wisdom practices. Each mode of vedanā is accompanied by its corresponding underlying tendency or obsession ("anusaya"). The underlying tendency for pleasant vedanā is the tendency toward lust, for unpleasant, the tendency toward aversion, and for neither pleasant nor unpleasant, the tendency toward ignorance. In the Canon it is stated  that meditating with concentration ("samādhi") on "vedanā" can lead to deep mindfulness ("sati") and clear comprehension ("") (see Table to the right). With this development, one can experience directly within oneself the reality of impermanence ("anicca") and the nature of attachment ("upādāna"). This in turn can ultimately lead to liberation of the mind ("nibbāna"). Alternate translations. Alternate translations for the term vedana are: