Mahatma is Sanskrit for "Great Soul" (महात्मा mahātmā: महा mahā (great) + आत्मं or आत्मन ātman [soul]); it is similar in usage to the modern Christian term saint. This epithet is commonly applied to prominent people like Mohandas Karamchand Gandhi and Jyotirao Phule. Many sources, such as Dutta and Robinson's Rabindranath Tagore: An Anthology, state that Rabindranath Tagore first accorded Gandhi this title. Others state that the title "Mahatma" was first accorded to Gandhi on January 21, 1915 by Nautamlal Bhagavanji Mehta at Kamribai School in Jetpur, India.
The term is also used to refer to adepts, liberated souls, or professionals.
The word, used in a technical sense, was popularised in theosophical literature in the late 19th century when Madame Helena P. Blavatsky, one of the founders of the Theosophical Society, claimed that her teachers were adepts or Mahatmas who reside in Tibet.
According to the Theosophical teachings, the Mahatmas are not disembodied beings, but highly evolved people involved in overseeing the spiritual growth of individuals and the development of civilisations. Blavatsky was the first person in modern times to claim contact with these Adepts, especially the "Masters" Koot Hoomi and Morya.
In September and October 1880, Blavatsky visited A. P. Sinnett at Simla in northern India. The serious interest of Sinnett in the Theosophical teachings of Mme. Blavatsky and the work of the Theosophical Society prompted Mme. Blavatsky to establish a contact by correspondence between Sinnett and the two adepts who were sponsoring the society, Koot Hoomi and Morya. From this correspondence Sinnett wrote The Occult World (1881) and Esoteric Buddhism (1883), both of which had an enormous influence in generating public interest in theosophy. The replies and explanations given by the Mahatmas to the questions by Sinnett are embodied in their letters from 1880 to 1885, published in London in 1923 as The Mahatma Letters to Sinnett. The Mahatmas also corresponded with a number of other persons during the early years of the Theosophical Society. Many of these letters have been published in two volumes titled Letters from the Masters of the Wisdom, Series 1 and Series 2.
There has been a great deal of controversy concerning the existence of these particular adepts. Blavatsky's critics have doubted the existence of her Masters. See, for example, W.E. Coleman's "exposes." More than twenty five individuals testified to having seen and been in contact with these Mahatmas during Blavatsky's lifetime. In recent years, K. Paul Johnson has promoted an interesting but controversial theory about the Masters.
After Blavatsky's death in 1891, numerous individuals have claimed to be in contact with her Adept Teachers and have stated that they were new "messengers" of the Masters conveying various esoteric teachings. Currently various New Age, metaphysical, and religious organizations refer to them as Ascended Masters, although their character and teachings are in several respects different from those described by Theosophical writers.