Sen, Keshub Chunder ( Keshab Chandra Sen) (1838–84). Indian reformer, and third leader of Brahmo Samāj. He joined the Brahmo Samāj in 1857, working with Debendranāth Tagore to promote its aims, and lecturing widely in English on theistic doctrine and Brahmo philosophy, establishing branches of the Samāj in Bombay, Madras, and other centres.

Throughout his life Sen claimed to have had mystical experiences. He almost became a Christian in 1866, the only obstacle being an inability to accept the uniqueness of Christ, though he turned against the philosophical system of Hinduism, including Vedānta, supporting widow remarriage and repudiating the wearing of the sacred thread (upanayana), finally breaking with Debendranāth Tagore in 1865. In 1866 he established the Bhāratvarshīya Brahmo Samāj, which preached the brotherhood of all under the Fatherhood of God, a teaching enshrined in the Śloka-saṃgraha scriptures.

Sen later adopted still more social reforms. He relied increasingly on direct inspiration, which enabled him, despite his previous opposition to child-marriage, to marry his 13-year-old daughter to a Hindu prince. Many of his followers abandoned him for this, setting up in 1878 Sādhāran (General) Brahmo Samāj. In 1879 he proclaimed a New Dispensation (Nava Vidhāna) to supplant Christianity. He chose twelve disciples, promulgated the Motherhood of God, revived the āratī and homa ceremonies, the Durgā Pūjā festival, and the religious dance of Caitanya, while urging that idolatry and polytheism were forms of theism.

Keshub Chandra Sen: see SEN, KESHUB.