Though developed and nurtured by scholars of orthodox schools of Hinduism, Sanskrit has been the language for some of the key literary works and theology of heterodox schools of Indian philosophies such as Buddhism and Jainism. The structure and capabilities of the Classical Sanskrit language launched ancient Indian speculations about "the nature and function of language", what is the relationship between words and their meanings in the context of a community of speakers, whether this relationship is objective or subjective, discovered or is created, how individuals learn and relate to the world around them through language, and about the limits of language? They speculated on the role of language, the ontological status of painting word-images through sound, and the need for rules so that it can serve as a means for a community of speakers, separated by geography or time, to share and understand profound ideas from each other. These speculations became particularly important to the Mīmāṃsā and the Nyaya schools of Hindu philosophy, and later to Vedanta and Mahayana Buddhism, states Frits Staal—a scholar of Linguistics with a focus on Indian philosophies and Sanskrit. Though written in a number of different scripts, the dominant language of Hindu texts has been Sanskrit. It or a hybrid form of Sanskrit became the preferred language of Mahayana Buddhism scholarship; for example, one of the early and influential Buddhist philosophers, Nagarjuna (~200 CE), used Classical Sanskrit as the language for his texts. According to Renou, Sanskrit had a limited role in the Theravada tradition (formerly known as the Hinayana) but the Prakrit works that have survived are of doubtful authenticity. Some of the canonical fragments of the early Buddhist traditions, discovered in the 20th century, suggest the early Buddhist traditions used an imperfect and reasonably good Sanskrit, sometimes with a Pali syntax, states Renou. The Mahāsāṃghika and Mahavastu, in their late Hinayana forms, used hybrid Sanskrit for their literature. Sanskrit was also the language of some of the oldest surviving, authoritative and much followed philosophical works of Jainism such as the "Tattvartha Sutra" by Umaswati.