古代インドにおける語源学学習の四目的

According to Yāska, Sanskrit etymology (nirukta, nirvacana) fulfills the following four purposes:
1. One can understand the true meanings of ritual formulas (mantreṣv arthapratyayaḥ ) containing etymologically difficult words that cannot be accounted for through grammar (vyākaraṇa) alone.
2. One can learn how to analyze such words grammatically (padavibhāga).
3. One can, by means of Yāska’s interpretations presented for given ritual formulas, specify who is the main deity (daivata) to whom the ritual formula in question is directed.
4. One will be praised for knowing the true meanings of etymologically difficult words and thereby of ritual formulas containing them (arthajñapraśaṁsā).

Point 4 clearly shows that the chief aim of Yāska’s Nirukta is to enable one to understand the true meanings of ritual formulas (Point 1). In the course of etymologizing difficult words that do not comply with grammatical rules, the way of grammatically analyzing them is indicated (Point 2). It is for this reason that etymology is said to be a complement to grammar (vyākaraṇasya kārtsnyam). Needless to say, when reciting the ritual formula, one has to know which deity the formula is dedicated to (Point 3). Thus, we see that Yāska’s arguments center on how to employ ritual formulas properly: Through Yāska’s Nirukta, one can identify the main deity of the ritual formula (Point 3), learn how to analyze difficult words therein (Point 2), and thereby understand their true meanings and hence the whole meaning of the formula (Point 1). Employed with this knowledge, the formula will become effective, bringing about the desired object(s).
For ritual formulas to be efficacious, it is first of all necessary to pronounce them correctly with respect to word forms, their accents, and so forth. It is stated in Kātyāyana’s Sarvānukramaṇī (SA [1.5–6]) that the knowledge of the following is also required for the effective use of ritual formulas: 1) the inspired poet (rṣi) who ‘saw’ the formula; 2) its meter (chandas); 3) its presiding deity (daivata); and according to Yāska, one further factor is indispensable: the knowledge of the formula’s meaning (artha). This view of Yāska’s is neatly embodied in the following verse quoted in the Nirukta to establish the significance of knowing the meanings of ritual formulas (Nirukta 1.18 [40.18–19]):

yád grhītám avijñataṃ 　nigádenaiva śábdyate |
ánagnāv íva śuṣkaidhó　ná táj jvalati kárhi cit ||
“What has been grasped (learned) without being understood and is uttered by mere recitation, that never blazes, like dry wood when there is no fire.”

As a historical background to Yāska’s idea described above, it may be suggested that, the more the meanings of difficult Vedic words, especially those of the Rgveda, ceased to be understood, the more such meanings came to be considered as imbued with the mysterious power which should lead to the success of Vedic rituals. It may be noted that Yāska’s analysis of the word artha ‘meaning’ as araṇastha ‘what is situated in a foreign area’ (Nirukta 7.18 [41.18]) tells us that Yāska regards the word-meaning as something highly secret.