This mainly a continuation of my ongoïng argument with u/srkris on the nature of the topic stated in the title. However, I hope that this will help to inform others of it. Obviously, I am not a historical linguist, but I shall make sure to underline where ever I'm using my own reasoning to achieve a conclusion and where I am referring to real papers and books written by professionals.

To Srkris in particular: I would like to implore you to read everything I'm about to layout thoroughly. My experiences in our previöus bouts have shown me time and time again that you seem to not fully read my arguments and/or consistently misunderstand what I'm saying.

To begin with I would like to state what exactly it is I'm trying to prove:

>The Old-Indo-Aryan (OIA) stage of languages/diälects (hereafter just 'forms of OIA') is one that involved more than just pure attested Vedic and Classical Sanskrit. Vedic does not simply evolve into Classical and Classical is not the sole mother language of all the MIA languages. This does not imply that there were parallel non-Vedic or proto-Pāli civilizations in South Asia; rather, all forms of OIA would still be spoken by people of what we would consider the same culture and civilization as Vedic and post-Vedic peoples. All forms of OIA would still closely resemble and be mutually intelligible with what we call Vedic and Classical Sanskrit. Moreover Sanskrit was no longer the primary spoken language of the sub-continent by the 4^(th) BCE (c. 400-300 BCE) at the latest.

Now, let us get started.

The first thing I would like to bring into consideration is a call to reason based on the structure of Early Vedic sociëty. Given that the people of the RV were organized into various semi-nomadic "tribes" or viśaḥ (ref. the Jamison & Brereton RV, introduction), it is not difficult to reason that many of such viśaḥ did not conform to the standards of Vedic Sanskrit as we have it in the RV. In fact, I find it hard to believe that many different groups inconsistently in contact with one another would speak the exact same homogeneous form OIA for hundreds of years.

Next, let us examine the early OIA evidence that points towards non-Vedic OIA. Primarily, we have the OIA attested in 14th century BCE Mittani documents that shows distinct phonology from attested Vedic, primarily in the form of the presence of voiced fricatives: Bi-ir-ia-ma-aš-da = priyamazd(h)a instead of the Vedic form of priyamaidha (Cl. -mēdha) and vašana(š)šaya = vāžhanasya instead of Vedic vāhanasya (ref. Witzel Autochthonous Aryans? §18). I know my opponent has previöusly raised an objection on the nature of this language, questioning whether it could not be Iranian, but this can be resolved by the fact that the Mittani documents rather helpfully mention the Vedic Gods by name (again see Autochthonous Aryans? §18). This, in itself, should be enough. It is a clearly a distinct non-Vedic form of OIA. But let us say you want to consider this an exception since it migrated so far from India; surely the rest of OIA in India is just "Vedic".

Then, we can examine the evidence within the Vedic corpus itself as well. Contrary to popular belief, even it is not as homogeneous as people might think. Consider the RV ळ vs variöus later texts preserving the older ड, consider KS preserving the original श्छ instead of च्छ or छ, consider क्श in place of ख्य among the Kurus, the preservation of सुवर् in TS, and य्म instead of ज्म in variöus texts including KpS (Micheal Witzel, Tracing the Vedic dialects, §6).

But even those are just phonetic differences; I will quote Witzel on actual textual citations that speak of different forms of speech:

• the famous ŚB quotation, he 'lavo he 'lavo, spoken by the Asuras, which is believed to be from an early Eastern 'Prākṛt' for: he (a)rayaḥ.
• the better speech of the Northerners: KB 7.6
• the higher tones of the Kurus, Pañcālas: ŚBM 3.2.3.15; or Kurus, Mahāvṛṣas: ŚBK 4.2.3.15 uttarāhi/°hai)
• the son of a king of Kosala speaks "like the Easterners": JB 1. 338 = ed.Caland §115
• the names of Agni/Rudra in the East viz. West: Śarva with the Easterners, Bhava with the Bāhīkas: ŚB 1. 7. 3. 8, cf. 6. 1. 3. 11-15
• the gods, Gandharvas, Asuras, and men speak differently, ŚB 10. 6. 4. 1
• so do the gods on one hand (rātrīm) and the author of the passage in question (rātrim), MS 1. 5. 12 : 81. 3-4
• the dīkṣita has his own language
• so have the Vrātyas (cf. H. Falk, Bruderschaft)
• note the difference in the language of women: they speak candratara, probably "more clearly", with higher pitch; at RV 10. 145. 2, a woman uses the younger (and more popular) kuru instead of kṛṇu.
• (All citations to other papers and footnotes can be reviewed in Tracing the Vedic dialects on pp. 4-5)

But let us say all this is not convincing enough. Let us say all of these citations are somehow only minor diälectical differences and are still the same Vedic. Can we find traces of other forms of OIA even then? Yes, yes we can.

Consider the Proto-Indo-Iranian root *źʰáȷ́źʰ- "to greatly laugh; roar" which is a reduplication of *źʰas- (whence हस्) "laugh". In Vedic, this root has devoiced the *gẓʰ in to kṣ, thus forming the root जक्ष् of the same meaning. However, there is one exception to this in the form of RV hapax legomenon of जज्झतीः (also written जझ्झतीः). It should be pretty clear that this is not onomatopoeia (Mayrhofer, Etymologisches Wörterbuch Des Altindoarischen Volume 1, pg 562). One can quite clearly see that the poët has clearly borrowed the word from an otherwise unattested form of OIA, and not knowing how to say gẓ, transformed the word into jjh, just as later Prākṛts would transform kṣ to cch.

In case this seems a stretch, we can see the influences of forms of OIA that preserved the voicing of this cluster as far as Pāli and the Prākṛts: (ug-/pag)ggharati not reflecting Skt. क्षरति; jhāyati, not reflecting Skt. क्षायति; jhijjai/jhīṇa not reflecting Skt. क्षिणोति; and of course jagghati reflecting a relation closer to *जज्झति and not Skt. जक्षिति (Oberlies' Middle Indo-Aryan and the Vedic Dialects). My opponent's counterargument that these are simply the influences of some infiltrating Avestan related language cannot reasonably be taken seriously as cognate roots for क्षै and जक्ष्/हस् seem not to even exist in Proto-Iranian (as far as I can see) and by the fact that this phenomenon is observed as far back as Vedic. It is for the same latter reason that we cannot just disregard this as plane irregularity.

Pāli and the other Prākṛts are also useful in showing traces of variöus other archaic features that are not present in attested OIA; for example: PIE *-ṛh2- is continued by īr in Sanskrit like in tīrtha but Pkt. tūha suggests *tūrtha as well. The Pāli and Aśokan (i)dha and (hi)da continue PIE *dʰe whereas the Sanskrit form has already debuccalized to इह. A more complete list can be found in Oberlies' Middle Indo-Aryan and the Vedic Dialects, at §2.1.

But this is not all. Consider the regular external sandhi below:

>aḥ + X (voiced consonant or a) = a + u + X = au (Cl. ō) + X

This is, of course, the remnant of Proto-Indo-Aryan final sibilants, which became *z in such positions. When this *z was dropped from Vedic, it became u. However, in other places, the dropped *z was also transformed into an i: *azdhi → aidhi (एधि). Thus, one might expect that we should see aḥ + X becoming ai (Cl. ē) + X, and indeed there are a very small number of instances of this in the RV for a single form: सूरः॑ (the gen. sg. of स्वर्); ex. 1. 34. 5: सूरः॑ दुहि॒ता → सूरे॑ दुहि॒ता. Everywhere else in all of attested Sanskrit, only conversions to u are seen. (Micheal Witzel, Tracing the Vedic dialects, §6.7) (Witzel does suggest that the near absence of the i version in the RV could be because of redactors, but underlines it by saying that more instances preserved through misunderstanding would be expected). Despite this, we can reason that a form of OIA must have existed which predominantly used the i version of this sandhi as it was popular enough for the suffix of languages like Eastern Ashokan Prākṛt to become -e instead of -o for etymologically -aḥ ending forms (Tracing the Vedic dialects, §6.7 for the prākṛtic -e ending).

Thus, the evidence presented above quite clearly shows that Vedic must have had contemporaries.

Next, let us move on to proving the non-linear development of OIA into MIA.

This is mostly done already by the evidence presented above confirming the influence of other forms of OIA on the Prākṛts. However, we have further evidence to prove that Classical Sanskrit is not the sole parent. Consider that Pāli exhibits the masc. pl. ending āse/āso), and the a-ending inst. pl. ehi which are continuations of Vedic endings -आसः and -एभिः, which are completely absent in Classical. So too with the infinitive in -tave, the absolutive in -yā, and the participle in -āvi(n). A more thorough list can be found in Oberlies' Pāli Grammar on page 8 in the introduction. Page 9 also starts a 70 word list of words found in Vedic and Pāli but not in Classical, which is described as only a "first attempt" at cataloguing such a category.

(Reasoning) Doubtless, my opponent will object that the evidence I have presented here is insufficient as the majority of Pāli words can still be derived from Classical Sanskrit, but this is irrelevant. I have no doubt that the majority of Pāli words can find cognates in a large number of later Prākṛts, but this does not make Pāli their progenitor. As I have stated previöusly the forms of OIA would still be similar enough to understand one another, thus making it possible to derive Pāli from any one of them. For example, you can even derive Pāli medhā from the Mittani IA mazdha if you wanted.

Then there is non-linear development of Classical Sanskrit. Observe that many Vedic forms are largely r-centered: लघु is unattested in the RV, चलति is similarly missing in the TS, MS, and RV (from find command on sanskritdocs and titus). These forms of OIA are called the r-diälects because they do not preserve the original r-l distinction of PII and PIE. However other diälects preserved this distinction and these mixed with the r-diälects in Classical along with minor contributions from possible l only diälects as well. Thus we have variöus doublets in Classical, which are sometimes synonyms but also often take up different semantics: चरति-चलति, रघु-लघु, शुक्र-शुक्ल, लिख्-रेखा etc. (T. Burrow, A Reconsideration of Fortunatov's Law). I would also recommend reviewing Some Aspects of Pre-Historic Indo-Aryan by Madhav Deshpande for a greater overview of the more complex development of Classical Sanskrit.

Finally we come to the last portion of this argument: Sanskrit's decline as the primary spoken language.

First, to establish a base line for the latest Sanskrit disappears as a vernacular, we have only to look at the Aśokan Edicts which are clearly written in Prakrit and are usually dated to the 3rd century BCE (300 to 200 BCE) (Masica, Colin, The Indo-Aryan languages). My opponent has previously claimed that Aśokan Prakrit (which seems to be early Magadhi itself?) is somehow just vernacular Sanskrit, but any reading of the edicts should prove otherwise. Take, for example, a sentence from Pillar VII:

>एतं देवानंपिये पियदसि लाजा हेवं आहा। एस मे हुथा। अतिकंतं च अंतलं हेवं इछिसु लाजाने कथं जने अनुलुपाया धंमवढिया वढेया ति; नो चु जने अनुलुपाया धंमवढिया वढिथा; से किनसु जने अनुपटिपजेया; किनसु जने अनुलुपाया धंमवढिया वढिथा ति; किनसु कानि अभ्युंनामयेहं धंमवढिया ति।

This is obviously not Sanskrit, and is not considered Sanskrit by literally any credible source that I could find. Consider also that this was an official formal edict, not necessarily even the common vernacular (compare more latinized formal English with common vernacular forms of English). Thus, we may reason that the common speech might have been even further from Sanskrit than what we have presented to us.

However, a language's first attestation does not imply that it first developed then and there. Indeed, we can reason that it probably existed at least a century before, if not more, given the extensive sound changes that would need to have occurred between Sanskrit and Ásokan.

We can look at the Buddha for more concrete proof of this, as he is normally considered to have spoken some kind of Prakrit and not Sanskrit (Norman K. R., Philological Approach To Buddhism, IV). It is generally agreed upon that the Buddha died sometime around 400 BCE (ibid. pg 38). Therefore, we can conclude, that at the very least Sanskrit was not the language of the people by the 4th century BCE.

Thank you for reading.

पुण्यं प्रशस्तम्।

Works Cited:

1. The Rigveda The Earliest Poetry Of India by Jamison & Brereton
2. Autochthonous Aryans? The Evidence from Old Indian and Iranian Texts by Micheal Witzel
3. Tracing the Vedic Dialects by ibid.
4. Etymologisches Wörterbuch Des Altindoarischen Volume 1 by Mayrhofer, Manfred
5. Middle Indo-Aryan and (the) Vedic (Dialects) (Miscellanea Palica VII) by Thomas Oberlies
6. Pāli: A Grammar Of The Language Of The Theravāda Tipiṭaka by ibid.
7. A Reconsideration of Fortunatov's Law by T. Burrow
8. Some Aspects of Pre-Historic Indo-Aryan by Madhav Deshpande
9. The Indo-Aryan languages by Masica, Colin
10. Edicts Of Ashoka by the Beloved of the Gods Possessing Loving Sight, edited by G. Srinivasa Murti
11. A Philological Approach To Buddhism by Norman K. R.