A couple of definitions so that we are all on the same page:paramattha (-sacca, -vacana, -desanā):
'truth (or term, exposition) that is true in the highest (or ultimate) sense', as contrasted with the 'conventional truth' (vohāra-sacca), which is also called 'commonly accepted truth' (sammuti-sacca; in Skr: samvrti-satya). The Buddha, in explaining his doctrine, sometimes used conventional language and sometimes the philosophical mode of expression which is in accordance whith undeluded insight into reality. In that ultimate sense, existence is a mere process of physical and mental phenomena within which, or beyond which, no real ego-entity nor any abiding substance can ever be found. Thus, whenever the Suttas speak of man, woman or person, or of the rebirth of a being, this must not be taken as being valid in the ultimate sense, but as a mere conventional mode of speech (vohāra-vacana).
It is one of the main characteristics of the Abhidhamma Piṭaka, in distinction from most of the Sutta Piṭaka, that it does not employ conventional language, but deals only with ultimates, or realities in the highest sense (paramattha-dhammā). But also in the Sutta Piṭaka there are many expositions in terms of ultimate language (paramattha-desanā), namely, wherever these texts deal with the groups (khandha), elements (dhātu) or sense-bases (āyatana), and their components; and wherever the 3 characteristics (ti-lakkhaṇa, q.v.) are applied. The majority of Sutta texts, however, use the conventional language, as appropriate in a practical or ethical context, because it "would not be right to say that 'the groups' (khandha) feel shame, etc."
It should be noted, however, that also statements of the Buddha couched in conventional language, are called 'truth' (vohāra-sacca), being correct on their own level, which does not contradict the fact that such statements ultimately refer to impermanent and impersonal processes.
The two truths - ultimate and conventional - appear in that form only in the commentaries, but are implied in a Sutta-distinction of 'explicit (or direct) meaning' (nītattha, q.v.) and 'implicit meaning (to be inferred)' (neyyattha). Further, the Buddha repeatedly mentioned his reservations when using conventional speech, e.g. in D. 9: "These are merely names, expressions, turns of speech, designations in common use in the world, which the Perfect Qne (Tathāgata) uses without misapprehending them." See also S. I. 25.
The term paramattha, in the sense here used, occurs in the first para. of the Kathāvatthu, a work of the Abhidhamma Piṭaka (s. Guide, p. 62). (App: vohāra).
The commentarial discussions on these truths (Com. to D. 9 and M. 5) have not yet been translated in full. On these see K N. Jayatilleke, Early Buddhist Theory of Knowledge (London, 1963), pp. 361ff.
In Mahāyana, the Mādhyamika school has given a prominent place to the teaching of the two truths.http://www.budsas.org/ebud/bud-dict/dic3_p.htmdhamma
: lit. the 'bearer', constitution (or nature of a thing), norm, law (jus), doctrine; justice, righteousness; quality; thing, object of mind (s. āyatana) 'phenomenon'. In all these meanings the word 'dhamma' is to be met with in the texts. The Com. to D. instances 4 applications of this term guṇa (quality, virtue), desanā (instruction), pariyatti (text), nijjīvatā (soullessness, e.g. "all dhammā, phenomena, are impersonal," etc.). The Com. to Dhs. has hetu (condition) instead of desanā. Thus, the analytical knowledge of the law (s. paṭisambhidā) is explained in Vis.M. XIV. and in Vibh. as hetumhi ñāṇa, knowledge of the conditions.
The Dhamma, as the liberating law discovered and proclaimed by the Buddha, is summed up in the 4 Noble Truths (s. sacca). It forms one of the 3 Gems (ti-ratana, q.v.) and one of the 10 recollections (anussati q.v.).
Dhamma, as object of mind (dhammāyatana, s. āyatana) may be anything past, present or future, corporeal or mental, conditioned or not (cf. saṅkhāra, 4), real or imaginary.
dhamma-cakka: The 'Wheel (realm) of the Law', is a name for the doctrine 'set rolling' (established) by the Buddha, i.e. the 4 Noble Truths (sacca, q.v.).
"The Perfect One, o monks, the Holy One, fully Enlightened One, in the Deer Park at Isipatana near Benares, has set rolling (established) the unsurpassed Wheel (realm) of the Law" (M. 141). Cf. cakka.http://www.budsas.org/ebud/bud-dict/dic3_d.htm
Citta and cetasika are mental phenomena, nama, which are real in the ultimate sense. Ultimate realities or paramattha dhammas have each their own characteristic their own function, they are true for everybody. There are four paramattha dhammas
Citta, cetasika and rupa are sankhara dhammas, conditioned dhammas; they do not arise by themselves, each of them is conditioned by other phenomena. Citta for example, does not arise by itself, it is conditioned by the accompanying cetasikas.
Nibbana is the unconditioned dhamma, visankhara dhamma or asankhata dhamma; it does not arise and fall away. Nibbana is the object of the supramundane citta, lokuttara citta, arising at the moment of enlightenment. What we call in conventional language a person is in the absolute or ultimate sense only citta, cetasika and rupa. There is no lasting person or self, there are only citta, cetasika and rupa which arise and then fall away immediately. Citta and cetasika are both namas, realities which can experience something, whereas rupa does not experience anything. (p.4 Cetasikas by Nina van Gorkom, Zolag, 1999).