The technique has been described as both religious and non-religious, as an aspect of a new religious movement, as rooted in Hinduism,:p 188 and as a non-religious practice for self-development.:p 4 Over its 50-year history the technique has had high visibility in the mass media and effective global propagation, and used celebrity and scientific endorsements as a marketing tool. Advanced courses supplement the TM technique and include an advanced meditation called the TM-Sidhi program. In 1970 the Science of Creative Intelligence, described as "modern science with ancient Vedic science", became the theoretical basis for the Transcendental Meditation technique. The Science of Creative Intelligence is a pseudoscience.
The technique is recommended for 20 minutes twice per day. According to the Maharishi, "bubbles of thought are produced in a stream one after the other", and the Transcendental Meditation technique consists of experiencing a "proper thought" in its more subtle states "until its subtlest state is experienced and transcended".:pp 46–52 Because it is mantra based, the technique "ostensibly meets the working definition of a concentration practice"; however, the TM organization says that "focused attention" is not prescribed, and that the "aim is an unified and open attentional stance". Other authors describe the technique as an easy, natural technique or process,:340–341 and a "wakeful hypometabolic physiologic state". Practice of the technique includes a process called "unstressing" which combines "effortless relaxation with spontaneous imagery and emotion". TM teachers caution their students not to be alarmed by random thoughts and to "attend" to the mantra. Scottish chess grandmaster Jonathan Rowson has said that his TM practice gives "a feeling of serenity, energy and balance", but does not provide "any powerful insight into your own mind". Laura Tenant, a reporter for The Independent, said that her TM experience includes going "to a place which was neither wakefulness, sleeping or dreaming", and becoming "detached from my physical self". Worldwide, four to ten million people are reported to be practitioners.
The TM technique consists of silently repeating a mantra with "gentle effortlessness" while sitting comfortably with eyes closed and without assuming any special yoga position. The mantra is said to be a vehicle that allows the individual's attention to travel naturally to a less active, quieter style of mental functioning.:pp 16–20 TM meditators are instructed to keep their mantra secret to ensure maximum results ("speaking it aloud, apparently defeats the purpose"), to avoid confusion in the mind of the meditators, and as a "protection against inaccurate teaching".
The Maharishi is reported to have standardized and "mechanized" the mantra selection process by using a specific set of mantras and making the selection process "foolproof". Professor of psychiatry Norman E. Rosenthal writes that during the training given by a certified TM teacher, "each student is assigned a specific mantra or sound, with instructions on its proper use". The Maharishi said that the selection of a proper thought or mantra "becomes increasingly important when we consider that the power of thought increases when the thought is appreciated in its infant stages of development".:p 51 He said that mantras chosen for initiates should "resonate to the pulse of his thought and as it resonates, create an increasingly soothing influence", and that the chosen mantra's vibrations "harmonize" with the meditator, and suits their "nature and way of life". TM students are therefore given a "specially suited mantra".:p 188 Author George D. Chryssides writes that according to the Maharishi, "using just any mantra can be dangerous"; the mantras for "householders" and for recluses differ. The Transcendental Meditation mantras are appropriate mantras for householders, while most mantras commonly found in books, such as "Om", are mantras for recluses and "can cause a person to withdraw from life".
Former TM teacher and author Lola Williamson reports that she told her TM students that their mantra was chosen for them based on their personal interview, while sociologist Roy Wallis, religious scholar J. Gordon Melton and Bainbridge write that the mantras are assigned by age and gender. In 1984, 16 mantras were published in Omni magazine based on information from "disaffected TM teachers". According to Chryssides, TM teachers say that the promised results are dependent on a trained Transcendental Meditation teacher choosing the mantra for their student.