The Brihadaranyaka Upanishad (बृहदारण्यक उपनिषद्, ) is one of the Principal Upanishads and one of the first Upanishadic scriptures of Hinduism. A key scripture to various schools of Hinduism, the Brihadaranyaka Upanisad is tenth in the Muktikā or "canon of 108 Upanishads". The Brihadaranyaka Upanishad is estimated to have been composed about 7th–6th century BCE, excluding some parts estimated to have been composed after the Chandogya Upanishad. The Sanskrit language text is contained within the Shatapatha Brahmana, which is itself a part of the Shukla Yajur Veda. The Brihadaranyaka Upanishad is a treatise on Ātman (Self), includes passages on metaphysics, ethics and a yearning for knowledge that influenced various Indian religions, ancient and medieval scholars, and attracted secondary works such as those by Adi Shankara and Madhvacharya. The chronology of Brihadaranyaka Upanishad, like other Upanishads, is uncertain and contested. The chronology is difficult to resolve because all opinions rest on scanty evidence, an analysis of archaism, style and repetitions across texts, driven by assumptions about likely evolution of ideas, and on presumptions about which philosophy might have influenced which other Indian philosophies. Patrick Olivelle states, "in spite of claims made by some, in reality, any dating of these documents (early Upanishads) that attempts a precision closer than a few centuries is as stable as a house of cards". The chronology and authorship of Brihadaranyaka Upanishad, along with Chandogya and Kaushitaki Upanishads, is further complicated because they are compiled anthologies of literature that must have existed as independent texts before they became part of these Upanishads. The exact year, and even the century of the Upanishad composition is unknown. Scholars have offered different estimates ranging from 900 BCE to 600 BCE, all preceding Buddhism. Brihadaranyaka is one of the first Upanishads, along with that of Jaiminiya Upanishad and Chandogya Upanishads.