deduced. Despite differences in the analysis from that of modern linguistics, Pāṇini's work has been found valuable and the most advanced analysis of linguistics until the twentieth century. Pāṇini's comprehensive and scientific theory of grammar is conventionally taken to mark the start of Classical Sanskrit. His systematic treatise inspired and made Sanskrit the preeminent Indian language of learning and literature for two millennia. It is unclear whether Pāṇini himself wrote his treatise or he orally created the detailed and sophisticated treatise then transmitted it through his students. Modern scholarship generally accepts that he knew of a form of writing, based on references to words such as Lipi ('script') and ('scribe') in section 3.2 of the . The Classical Sanskrit language formalized by Pāṇini, states Renou, is "not an impoverished language", rather it is "a controlled and a restrained language from which archaisms and unnecessary formal alternatives were excluded". The Classical form of the language simplified the sandhi rules but retained various aspects of the Vedic language, while adding rigor and flexibilities, so that it had sufficient means to express thoughts as well as being "capable of responding to the future increasing demands of an infinitely diversified literature", according to Renou. Pāṇini included numerous "optional rules" beyond the Vedic Sanskrit's framework, to respect liberty and creativity so that individual writers separated by geography or time would have the choice to express facts and their views in their own way, where tradition followed competitive forms of the Sanskrit language. The phonetic differences between Vedic Sanskrit and Classical Sanskrit, as discerned from the current state of the surviving literature, are negligible when compared to the intense change that must have occurred in the pre-Vedic period between the Proto-Indo-Aryan language and Vedic Sanskrit. The noticeable differences between the Vedic and the Classical Sanskrit include the much-expanded grammar and grammatical categories as well as the differences in the accent, the semantics and the syntax. There are also some differences between how some of the nouns and verbs end, as well as the sandhi rules, both internal and external. Quite many words found in the early Vedic Sanskrit language are never found in late Vedic Sanskrit or Classical Sanskrit literature, while some words have different and new meanings in Classical Sanskrit when contextually compared to the early Vedic Sanskrit literature. Arthur Macdonell was among the early colonial era scholars who summarized some of the differences between