Yogiraj Shri Vethathiri Maharishi (14 August 1911 – 28 March 2006) was a spiritual leader, world peace activist, scientist, philosopher, Ayurvedic and homeopathic practitioner, and founder-trustee of the World Community Service Center in 1958 in Chennai, India. His Theory of Universal Magnetism provides an alternative for the Big Bang theory, and includes the concepts of the evolution of atoms and God particles. He provided 14 principles for World Peace. He presented a blueprint at United Nations for World Peace. He founded over 300 yoga centres around the world and wrote about 80 books, many of which became academic textbooks. Tamil Nadu government has recently approved to teach his Simplified Kundalini Yoga at Schools. He was declared the 19th Siddha by the Dravidian University.
Shri Vethathiri Maharishi wrote over 3000 poems on philosophical subjects. In the Indian philosophical tradition, his philosophy corresponds to pure Advaita. His language and attitudes are contemporary, non-sectarian and non-dogmatic. He authored about 80 books in Tamil and English, and continued to write until his death.
Vethathiri strove to find answers to three questions: "What is God?" "What is life?" "Why is poverty in the world?" The search to find these answers as well as to further his lot in life led him into various fields of endeavour, including becoming a qualified practitioner of two systems of Indian indigenous medicine, Ayurveda and Siddha, and certified practitioner Homeopathy as well. Vethathiri led the life of a householder until he was 50, and then changed the course of his life from being a businessman to teach and write about his experiences of purported divine revelations. He published many books in English and Tamil. Between 1972–1993, he visited the US, Europe, Malaysia, Singapore, South Korea, Japan, and Mexico.