One medieval Hindu school sought immortality through mercury
Hindu philosophy calls itself darshana, a word meaning viewpoint, from a root meaning to see. The views were remarkably varied. Alongside rigorous logicians and dualists sat syncretic offshoots such as the Raseśvara, a Shaiva school that recommended mercury as a route to immortality.
The familiar list of six orthodox systems is itself a later construction. Vedantin scholars assembled the six-system scheme between the 12th and 16th centuries, and early Western Indologists adopted it, so it still colours modern accounts. The orthodox and heterodox labels were not clearly defined until the late medieval period, and some scholars doubt the division fits schools whose views kept evolving. The scholar Satoshi Ogura also cautions that Persianate ways of classifying Indian knowledge left their mark on later writing.
What united the orthodox schools was acceptance of the Vedas as authority and of an eternal Self, Atman. Samkhya, the oldest, with origins in the 1st millennium BCE, was dualist and agnostic about gods. It divided reality into witness-consciousness and nature and described three tendencies, the gunas: sattva, constructive and illuminating; rajas, restless and passionate; and tamas, dark and destructive. Its aim was to end suffering by realising that consciousness is distinct from nature, bringing a freedom called kaivalya.
Yoga borrowed Samkhya's psychology and metaphysics but accepted a personal god. Its key text is the Yoga Sutras attributed to Patanjali, though Max Müller suggested Patanjali may have represented the school without writing the sutras himself. Mīmāṃsā defended ritual and opposed asceticism and mysticism, while Vedanta, centred on the Upanishads, the Brahma Sutras and the Bhagavad Gita, became the dominant current after the medieval period.
The schools that rejected Vedic authority differed among themselves as much as from the orthodox. Charvaka materialists accepted free will and trusted perception alone as a reliable source of knowledge; the Ājīvika, also materialist, denied free will. Buddhism denied a permanent Self, while Jainism affirmed one and traced its teaching through twenty-four tirthankaras, from Rishabha to Mahavira. In the 14th century Madhavacharya, whom some identify with Vidyaranya, surveyed sixteen systems in his Sarva-Darsana-Sangraha.
Source: Hindu philosophy
