leading theologian of the Viśiṣṭādvaita (Qualified Nondualism) school of philosophy and founder of the Vaḍakalai, a subsect of the Śrīvaiṣṇavas, a religious movement of South India.

Vedāntadeśika was born into a distinguished Śrīvaiṣṇava family that followed the teachings of Rāmānuja, an 11th–12th-century saint. A precocious child, Vedāntadeśika was said to have been taken at the age of five to meet the sect's leader, Vātsya Varadācārya, who blessed him, saying he would in time be a great teacher and repudiate all false philosophers. Vedāntadeśika married and had a family but lived on alms in order to devote himself fully to his philosophic and literary efforts. He was a prolific writer in both Sanskrit and Tamil; his more than 100 works include commentaries on Vaiṣṇava scriptures; Nyāya-pariśuddhi, a comprehensive work on Viśiṣṭādvaita logic; Yādavābhyudaya, a poetic work on the life of Krishna; Saṅkalpa-sūryodaya, an allegorical drama; and devotional hymns.

According to Vedāntadeśika's interpretation of prapatti (surrender to the grace of God), some effort is required on the part of the worshiper to secure God's grace, just as the baby monkey must hold to its mother (the markaṭa-nyāya, or the “analogy of the monkey”). This view—together with ritual and linguistic differences—became the basis for the split between the two subsects, the Vaḍakalai and the Tengalai, who held that God's grace is unconditioned and that the human soul is as unassertive as a kitten carried by its mother.