Mahavira added celibacy (Brahmacharya) as the fifth major vow of Jainism. The previous four vows - Ahimsa (non-violence), Satya (truthfulness), Asteya (non-stealing), and Aparigraha (non-attachment) - were already taught by Parshvanatha, the 23rd Tirthankara. Mahavira institutionalized complete celibacy for monks.