the conundrum of duality.


Viññāṇa comes from the Sanskrit root √ ज्ञा jñā which has the meaning of experiencing & acknowledging.

However, because वि vi, (in vijñāna,) has the meaning of the English (a) , (dis) , (in) , (un) - that is to say disunion - it also conveys some significance of further conjecturing & investigating.
Why that?
Because indeed, viññāṇa is confronted in the third link (nidanā) of paṭiccasamuppāda, to the duality of the saṅkhāras in the previous link (saṅkhāra nidanā). That is to say to the kāyasaṅkhāro (assāsa & passāsā) - vacīsaṅkhāro (vitakka & vicārā) and the cittasaṅkhāro (saññā & vedanā) - the bodily, verbal and mental determinations.

Therefore, what viññāṇa experiences and acknowledges, is a duality that requires even more determinations to elucidate Ignorance (avijjā). For there is no ekodi (transcendental unification) in this duality. (Therefore, there is always some synergy (saṅkhāra) going on).
That is why name & form (nāmarūpa) and the spheres of senses (saḷāyatana) are further determined and layed down in the process.

That brings up the notion of "sense-viññāṇa," that has also to deal (at satta's level) with the duality of the external and internal spheres/bases/support (viz. the grounds or fields of experiences) of the senses (aka āyatanāni).
Also, one could ask himself, if there is not some embryonic stage of "nāmarūpa" in the saṅkhāra nidanā?


In summary, viññāṇa is always the acknowledgment of a synergism. Something that seems to trigger the need for further conjectures.


विज्ञान vijñāna [act. vijñā] n.
the act of distinguishing or discerning , understanding , comprehending , recognizing , intelligence , knowledge (AV.)

विज्ञा vijñā [vi-√ jñā] v.
- to become manifest , appear  (ChUp.)
- to distinguish , discern , observe , investigate , recognize , ascertain , know , understand (RV.)
- to be distinguished or discerned (ŚBr.)
- to wish to understand or know (TS. ChUp.)
- to make known , declare , report , communicate (ŚBr.) 
- to have right knowledge (KaṭhUp.)

वि vi
meaning " in two parts " ; and opp. to [ sam ]
It expresses "division" , "distinction".

√ ज्ञा jñā
pf. (anu, abhi, ava, ā, pari, pra, prati, vi, sam)
- to acknowledge , approve , allow (VS. AV. ŚBr.)
- experience, recognise, ascertain, investigate (RV.)
- to conjecture (AV.)





Also Ekodi:


एक Eka:
- One (RV.)
- the same , one and the same , identical (ŚBr. KātyŚr.)
- one of two or many, the one - the other, some, some - others (ŚBr. KātyŚr. MBh.) 
- alone , solitary , single , happening only once , that one only (RV.)

"Eka-g-gachati" in sanskrit, takes the somewhat meaning of: "he strives with the mind, to cause to become one and the same".
Trying to get to Eka-Udi


Eka+udi (transcend - escape)

उदि udi [ ud-√ i ]
See उद् Ud: (var. uc, uj, un, ut) - particle and prefix to verbs and nouns. (As implying superiority in place , rank , station , or power) up , upwards upon , on over , above. - and √ इ i : appear (BṛĀrUp.), arise from (ChUp.), escape (RV. AV. ŚBr.)

- to come out or arise from (RV. AV. ŚBr.)
- to escape (ChUp.)
- to go up to , proceed or move up , proceed (RV. AV. VS.)
- to rise (as the sun or a star ) (RV. VS. ŚBr. ChUp. VarBṛS.) 
- rise up against , march off (AV. MBh.)


Eka: [PTS]
1. “one” 
2. one,by oneself,one only,alone,solitary.

Udi (or udī) - artificial adj.form. fr.udeti,meaning “rising,excelling”.