When one thinks of संज्ञा-s and संज्ञासूत्राणि, it comes to mind that संज्ञा-s in अष्टाध्यायी are not just those, which are mentioned in संज्ञासूत्राणि. Rather, in अष्टाध्यायी, one would come across 4/5 distinct types of संज्ञा-s –
Type (1) In अष्टाध्यायी there are many such संज्ञा-s, i.e. words and terms, which were well-prevalent and did not need any explanation or definition. For example पाणिनि uses the term धातु straightaway right in (1-1-4). There is some detailing of it, not really an explanation or definition of it, that too, much later in भूवादयो धातवः (1-3-1) and सनाद्यन्ता धातवः (1-3-32). Thanks to Dr. H. N. Bhat for citing these.
Type (2) He uses as many as 43 प्रत्याहार-s, used as संज्ञा-s. It comes to mind that use of प्रत्याहार as संज्ञा was prevalent before पाणिनि. That must be why he does not explain what a प्रत्याहार is. He uses two such प्रत्याहार-संज्ञा-s straightaway, right in the first सूत्रम् – वृद्धिरादैच् (1-1-1). वृद्धिशब्दः संज्ञा; आदैचः संज्ञिनः [so said in महाभाष्यम् on (1-1-1)]. For संज्ञा-s of both types (1) and (2), the logic seems to be प्रख्यातस्य व्याख्यानेन किम् ? Why should there be elaboration of what is already well-known ?
Type (3) He coins his own संज्ञा-s using इत्-s. I discussed this in a special post on this. See https://grammarofsanskrit.wordpress.com/category/%E0%A4%B8%E0%A4%82%E0%A4%9C%E0%A5%8D%E0%A4%9E%E0%A4%95-s-or-%E0%A4%87%E0%A4%A4%E0%A5%8D-s-of-%E0%A4%AA%E0%A4%BE%E0%A4%A3%E0%A4%BF%E0%A4%A8%E0%A4%BF/
Type (4) पाणिनि does explain certain संज्ञा-s however, e.g. in अर्थवदधातुरप्रत्ययः प्रातिपदिकम् (1-2-45) he explains what a प्रातिपदिकम् is. I am left wondering, why प्रातिपदिकम् as a संज्ञा needed such explanation or definition. Was it not a प्रख्यातसंज्ञा ? Did he coin it by himself ? Or, was it not possibly defined as clearly as he did by saying अर्थवदधातुरप्रत्ययः प्रातिपदिकम्.
Type (5) One also comes across संज्ञा-s such as तु in न विभक्तौ तुस्माः (1-3-4) also चुटू (1-3-7). There are actually two संज्ञा-s here, चु and टु. Mr. D. V. N. Sharma, thanks to him, brought to my notice, that there is सूत्रम् – अणुदित्सवर्णस्य चाप्रत्ययः (1-1-69) which explains how these संज्ञा-s connote sets of consonants of their class, e.g. कु stands for the set of consonants of क्-वर्ग, चु stands for the set of consonants of च्-वर्ग, टु stands for the set of consonants of ट्-वर्ग, तु stands for the set of consonants of त्-वर्ग, पु stands for the set of consonants of प्-वर्ग. One is left to wonder whether these संज्ञा-s were coined by पाणिनि were prevalent before him.
One also comes across a problem that some संज्ञा-s seem to be coined with vowel-endings, which have nasal pronunciation, but the nasal pronunciation may often be not written in the written texts. For example in (4-1-2) स्वौजसमौट्छष्टाभ्याम्भिस्-ङेभ्याम्भ्यस्ङसिभ्याम्भ्यस्ङसोसाम्ङ्योस्सुप्॥ the first सुप्-प्रत्ययः is सु. Its application can be explained only by considering that it is actually सुँ not सु. Here सुँ has the nasal vowel ending उँ, which gets dropped according to उपदेशेऽजननुनासिक इत् (1-3-2) and तस्य लोपः (1-3-9). One can of course concede that it is difficult or not possible to write the nasal सुँ here, especially when it has a संधि with औ. One needs to take it however, that in the oral tradition, the pronunciation must have been insisted to be nasal. This underscores the importance of oral tradition and the need, that the oral tradition itself needs to be absolutely perfect !!
संज्ञा-s being of 4/5 types as above, one question of natural curiosity is “How many संज्ञा-s does one find in अष्टाध्यायी ? In response to my post on अधिकारसूत्राणि one Mr. सीताराम informed that there are 170 संज्ञासूत्राणि in अष्टाध्यायी. On 23 September 2011, Venetia-Ansell-महोदया had posted her study of some 80 संज्ञासूत्राणि. But, there are so many other संज्ञा-s, apart from those mentioned in संज्ञासूत्राणि.
In response to that post of Venetia-Ansell-महोदया, I had raised a basic question, “What is a संज्ञा ?”. Is it defined in अष्टाध्यायी ? Its first occurrence in अष्टाध्यायी is in पूर्वपरावरदक्षिणोत्तरापराधराणि व्यवस्थायामसंज्ञायाम् ॥ (1-1-34). Here the word संज्ञा is used by its antonym असंज्ञा. Obviously पाणिनि did not think it necessary to explain or define, what a संज्ञा is or what असंज्ञा is.
Actually the word संज्ञा seems to have different meanings in different contexts.
काशिनाथ-शास्त्री-अभ्यंकर-वर्यः compiled a dictionary of Sanskrit grammar. In that, the word संज्ञा is detailed as below –
“…. संज्ञा a technical term, a short wording to convey ample sense; a term to know general nature of things; convention; see also वृद्धिशब्दः संज्ञा; आदेचः संज्ञिनः (so said in महाभाष्यम् on (1-1-1). There are two main divisions of संज्ञा – कृत्रिमसंज्ञा or an artificial term such as टि, घु, or भ, which is merely conventional and अकृत्रिमसंज्ञा which refers to the literal sense conveyed by the word such as अव्यय, सर्वनाम and the like. Some grammar works like चन्द्र avoid purely conventional terms. These संज्ञा-s are necessary for every scientific treatise. In Panini’s grammar, there are the first two chapters, giving and explaining the technical terms whose number exceeds well-nigh hundred. ..”
In श्रीमद्भगवद्गीता also, this word संज्ञा is used in different senses, as in नायका मम सैन्यस्य संज्ञार्थं तान्ब्रवीमि ते (1-7) Here संज्ञार्थं = for (your) knowledge or information; भूतभावोद्भवकरो विसर्गः कर्मसंज्ञितः (8-3) Here कर्मसंज्ञितः = is called as Karma; द्वन्द्वैर्विमुक्ताः सुखदुःखसंज्ञैः (15-5) Here सुखदुःखसंज्ञैः = as connoted by सुखदुःख.
By parallelism between grammars of English and Sanskrit, one can also think that what is a ‘noun’ in English grammar is संज्ञा in Sanskrit grammar. But in English grammar we have “pronoun”, for which parallel word in Sanskrit grammar is सर्वनाम. As a corollary, one can say that नाम and संज्ञा are synonyms used in Sanskrit grammar.
In Apte’s dictionary, 12 meanings of the word संज्ञा are detailed, many with examples from Sanskrit texts. Appended thereto is also meaning of the compound word संज्ञासूत्रम् –
“… संज्ञा 1 Consciousness, अकरुण पुनः संज्ञाव्याधिं विधाय किमीहसे Māl.9.42; रतिखेदसमुत्पन्ना निद्रा संज्ञाविपर्ययः Ku.6.44. संज्ञा लभ्, आपद् or प्रतिपद् ‘to regain or recover one’s consciousness, come to one’s senses’. -2 Knowledge, understanding; नायका मम सैन्यस्य संज्ञार्थं तान् व्रवीमि ते Bg.1.7; Mb.12.153.63. -3 Intellect, mind; लोकतन्त्रं हि संज्ञाश्च सर्वमन्ने प्रतिष्ठितम् Mb.13.63.5. -4 A hint, sign, token, gesture; मुखापिंतैकाङ्गुलिसंज्ञयैव मा चापलायेति गणान् व्यनैषीत् Ku.3.41; उपलभ्य ततश्च धर्मसंज्ञाम् Bu. Ch.5.21; Bhāg. 6.7.17. -5 A name, designation, an appellation; often at the end of comp. in this sense; द्वन्द्वैर्विमुक्ताः सुखदुःखसंज्ञैः Bg.15.5. -6 (In grammar) Any name or noun having a special meaning, a proper name. -7 The technical name for an affix. -8 The Gāyatrī Mantra; see गायत्री. -9 A track, footstep. -10 Direction. -11 A technical term. -12 N. of the daughter of Viśvakarman and of wife of the sun, and of mother of Yama, Yamī, and the two Aśvins. संज्ञासूत्रम् – any Sūtra which teaches the meaning of a technical term. ..”
From all this discussion, I would say that संज्ञा-s detailed in संज्ञासूत्राणि is but a small subset of the set संज्ञा-s, which is much vaster.
By the way, there are as many as 7 सूत्राणि, all reading as संज्ञायाम् at (2-1-44), (3-3-109), (3-4-42), (4-1-72), (4-3-117), (6-2-159) and (8-2-11). There are also 18 more सूत्राणि, which start with the word संज्ञायाम्. All these are not संज्ञासूत्राणि. They rather seem to be विधिसूत्राणि, explaining what to do in the instance of a संज्ञा. संज्ञायाम् simply means “in the instance of a संज्ञा”.
There would be a large multitude of सूत्राणि, where one would come across the word संज्ञा. A novice, excited to learn about संज्ञा, should not get over-excited, whenever in any सूत्रम् he would notice the word संज्ञा.