”mental things, mental factors”, are those mental concomitants which are bound up with the simultaneously arising consciousness (citta = vin~n~a^na) and conditioned by its presence . Whereas in the Suttas all phenomena of existence are summed up under the aspect of 5 groups: corporeality, feeling, perception, mental formations, consciousness (s. khandha), the Abhidhamma as a rule treats them under the more philosophical 3 aspects: consciousness, mental factors and corporeality (citta, cetasika, rúpa). Thus, of these 3 aspects, the mental factors (cetasika) comprise feeling, perception and the 50 mental formations, altogether 52 mental concomitants. Of these, 25 are lofty qualities (either karmically wholesome or neutral), 14 karmically unwholesome, while 13 are as such karmically neutral, their karmical quality depending on whether they are associated with wholesome, unwholesome or neutral consciousness. For details s. Tab. II, III. Cf. prec. (App . )
This term oceurs often in the old sutta texts, but only as adj. (e.g. cetasikam sukham, etc.) or, at times, used as a sing. neut. noun (e.g. D. 1; p. 213, PTS). As a designation for mental factors, or concomitants of consciousness (citta-sampayutta^ dhamma^), it is frequently met with in Dhs. (§ 1189, 1512) as cetasika-dhamma, while in Vis.M., Abh. S., etc., cetasika is used also as a neuter noun, in the sense of mental phenomenon.