kusala: 'kammically wholesome' or 'profitable', salutary, morally good, (skillful) Connotations of the term, according to Com. (Aṭṭhasālinī), are: of good health, blameless, productive of favourable kamma-result, skillful. It should be noted that Com. excludes the meaning 'skillful', when the term is applied to states of consciousness.

It is defined in M. 9 as the 10 wholesome courses of action (s. kammapatha). In psychological terms, 'kammically wholesome' are all those kammical volitions (kamma-cetanā) and the consciousness and mental factors associated therewith, which are accompanied by 2 or 3 wholesome roots (s. mūla), i.e. by greedlessness (alobha) and hatelessness (adosa), and in some cases also by non-delusion (amoha: wisdom, understanding). Such states of consciousness are regarded as 'kammically wholesome' as they are causes of favourable kamma results and contain the seeds of a happy destiny or rebirth. From this explanation, two facts should be noted: (1) it is volition that makes a state of consciousness, or an act, 'good' or 'bad'; (2) the moral criterion in Buddhism is the presence or absence of the 3 wholesome or moral roots (s. mūla).

The above explanations refer to mundane (lokiya, q.v.) wholesome consciousness. Supermundane wholesome (lokuttara-kusala) states, i.e. the four paths of sanctity (s. ariyapuggala), have as results only the corresponding four fruitions; they do not constitute kamma, nor do they lead to rebirth, and this applies also to the good actions of an Arahat (Tab. I, 73-80) and his meditative states (Tab. 1, 81-89), which are all kammically inoperative (functional; s. kiriya).

 Kusala belongs to a threefold division of all consciousness, as found in the Abhidhamma (Dhs.), into wholesome (kusala), unwholesome (akusala) and kammically neutral (avyākata), which is the first of the triads (tika) in the Abhidhamma schedule (mātikā); s. Guide, pp. 4ff., 12ff; Vis.M. XIV, 83ff.

Buddhist Dictionary, Manual of Buddhist Terms and Doctrines, by NYANATILOKA MAHATHERA

善

kuśala

(Sanskrit; Pāli, kusala). Term of moral approbation denoting that which is good, virtuous, or wholesome, such as the ‘ten good actions’ (daśa-kuśala-karmapatha). Deeds which are kuśala produce good karma or merit (puṇya). They are thus conducive to happiness in general, prevent rebirth in negative modes of existence, and weaken ties to saṃsāra.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)

kusala: I. a. 善[巧]  II. n. 善

巴漢辭典 編者：(斗六) 廖文燦