Buddhism, founded by Gautama Buddha in the 6th century BCE, significantly influenced Indian society and thought.

Philosophically, Buddhism emphasized the Four Noble Truths and the Eightfold Path, advocating a middle way between asceticism and luxury. It rejected ritualism and caste exclusivity, promoting ethical conduct and personal effort for liberation. Concepts like impermanence and non-violence reshaped moral thinking.

Socially, Buddhism challenged Brahmanical dominance by opening its sangha to all castes and women. Monasteries became centers of learning and social service. Royal patronage, especially under Ashoka, facilitated its spread across India and beyond.

 Buddhism encouraged the use of Prakrit languages, making teachings accessible to common people. It stimulated art and architecture through stupas, viharas and chaityas, seen at Sanchi and Bharhut.

However, over time, institutionalization and dependence on patronage reduced its popular base in India.

 Buddhism profoundly shaped ancient Indian society by promoting ethical universalism, social inclusiveness and cultural creativity. Though it later declined in India, its philosophical and artistic legacy left a lasting imprint on Indian and Asian civilizations.