Ancient India produced atomists, sceptics, materialists and logicians long before modern science
Eastern philosophy spans Chinese, Japanese, Korean, Vietnamese and Indian traditions. India alone produced a startling range: one school argued the universe reduces to indivisible atoms, another built rigorous rules for valid knowledge, and heterodox movements entertained atheism and materialism. Some of the earliest surviving texts, the Upanishads, date from roughly 1000 to 500 BCE.
Indian schools were sorted as orthodox or heterodox, āstika or nāstika, by one of three tests: whether they accepted the Vedas as a source of knowledge, whether they affirmed Brahman and Atman, and whether they believed in an afterlife and gods. The usual list gives six orthodox schools, among them Nyaya, Samkhya, Yoga and Vedanta, and five heterodox ones including Jain, Buddhist and Cārvāka thought. Vidyaranya, by contrast, counted sixteen Hindu schools.
Their ideas differed sharply. Vaiśeṣika was a naturalist atomism that trusted only perception and inference, and sorted everything experienced into six categories such as substance, quality and activity. Nyāya held that suffering comes from ignorance and liberation from correct knowledge, and accepted four reliable routes to knowing, adding comparison and expert testimony to perception and inference. Samkhya was dualist, dividing reality into consciousness and matter, whereas Yoga, its close relative, allowed room for a God.
Concepts like dharma, karma, samsara, moksha and ahimsa run throughout. The tradition also reached beyond metaphysics: the Arthashastra, from around the 4th century BCE, dealt with politics, and the Kama Sutra with love. Hindu thought travelled east to the Srivijaya empire in Indonesia and the Khmer Empire in Cambodia.
The balance of schools shifted over time. The six-school scheme belonged to the Gupta golden age but faded by the late Middle Ages as Vaisheshika and Mīmāṃsā disappeared, while Vedanta sub-schools such as Advaita and Dvaita rose; bhakti devotion made Vedanta dominant after the medieval era. Buddhism largely vanished from India after the Muslim conquest, surviving in the Himalayas and the south. Logic kept evolving too: Raghunatha Siromani, who lived around 1460 to 1540, founded Navya-Nyāya, the new reason.
Source: Eastern philosophy
