The transpersonal is a term used by different schools of philosophy and psychology in order to describe experiences and worldviews that extend beyond the personal level of the psyche, and beyond mundane worldly events. The transpersonal has been defined as experiences in which the sense of identity or self extends beyond (trans) the individual or personal to encompass wider aspects of humankind, life, psyche or cosmos. On the other hand, transpersonal practices are those structured activities that focus on inducing transpersonal experiences. In the Textbook of Transpersonal Psychiatry and Psychology, Scotton defined the term as "development beyond conventional, personal or individual levels." It is associated with a developmental model of psychology that includes three successive stages: the prepersonal (before ego-formation), the personal (the functioning ego), and the transpersonal (ego remains available but is superseded by higher development). One of the founders of the field of transpersonal psychology, Stanislav Grof, has defined transpersonal states of awareness as such: "The common denominator of this otherwise rich and ramified group of phenomena is the feeling of the individual that his consciousness expanded beyond the usual ego boundaries and the limitations of time and space." The term is related to the terminology of peak experience, altered states of consciousness, and spiritual experiences. The term is also associated with psychedelic work, and psychotechnologies, that includes research with psychedelic plants and chemicals such as LSD, ibogaine, ketamine, peyote, ayahuasca and the vast variety of substances available to all human cultures throughout history. The term has an early precedent in the writing of philosopher William James, who used the term "Trans-personal" in one of his lectures from 1905. However, this early terminology, introduced by James, had a different meaning than the current one and its context was philosophy, not psychology, which is where the term is mostly used these days.