History of Transpersonal Psychology

The history of transpersonal psychology spans several decades, emerging from the confluence of humanistic psychology and spiritual traditions to address transcendent experiences and states of consciousness. This article traces the origins of the field, beginning with its philosophical and psychological precursors, including the influence of Eastern spiritual traditions and early thinkers like William James and Carl Jung. It explores the formal establishment of transpersonal psychology in the late 1960s, its evolution throughout the 1980s and 1990s, and the challenges it faced in gaining scientific legitimacy. The article also highlights the current trends and contributions of transpersonal psychology, particularly in mindfulness, consciousness studies, and therapeutic practices. Concluding with a reflection on the ongoing relevance of the field, it emphasizes transpersonal psychology’s potential to contribute to contemporary psychology and human development.

Introduction

Transpersonal psychology, established in the late 1960s, emerged as a response to the growing interest in integrating spirituality, consciousness, and psychological well-being. Its development reflected a desire to transcend the limitations of traditional psychological paradigms, which primarily focused on pathology, behavior, and the ego’s development. As a fourth force in psychology, following psychoanalysis, behaviorism, and humanistic psychology, transpersonal psychology sought to explore human experiences that extend beyond the self, including spiritual awakenings, mystical states, and self-transcendence (Vich, 1988). This integrative approach enabled the discipline to address the full spectrum of human consciousness, combining elements of Western psychology with insights from Eastern philosophies and indigenous traditions.

The field of transpersonal psychology was deeply influenced by key thinkers and practitioners in the mid-20th century, such as Abraham Maslow, Stanislav Grof, and Anthony Sutich, who emphasized the need for a psychology that considered higher states of consciousness and peak experiences (Grof, 2008). Maslow’s exploration of self-actualization and his recognition of peak experiences laid the foundation for a more holistic understanding of human potential. These pioneers envisioned a psychology that not only healed psychological suffering but also facilitated personal transformation and growth through spiritual and transpersonal experiences (Friedman & Hartelius, 2015). Their work initiated a new dialogue within psychology, challenging its focus on pathology and offering a more expansive view of the psyche.

Over the decades, transpersonal psychology has expanded its scope, addressing contemporary issues such as mindfulness, trauma, and ecological awareness. Its principles have permeated diverse fields such as psychotherapy, education, and consciousness studies, while the ongoing development of research methodologies has helped the field maintain scientific rigor (Hartelius, Caplan, & Rardin, 2007). Although it has faced challenges in gaining full acceptance within mainstream psychology, transpersonal psychology continues to influence therapeutic practices and interdisciplinary research, offering valuable insights into the nature of human consciousness and potential. The field’s evolution reflects a broader movement within psychology to integrate spiritual dimensions and transformative practices, maintaining relevance in an increasingly globalized and interconnected world.

Early Influences and Precursors

Philosophical and Religious Traditions

The roots of transpersonal psychology can be traced to ancient philosophical and religious traditions, particularly those that emphasized the nature of consciousness and spiritual experience. Eastern spiritual traditions such as Hinduism, Buddhism, and Taoism have long explored themes of self-transcendence, enlightenment, and the dissolution of the ego, which resonate with core ideas in transpersonal psychology. For example, the concept of moksha in Hinduism and nirvana in Buddhism reflects a transcendent state beyond the limitations of the ego and material existence, ideas that have deeply influenced transpersonal thought (Forman, 1998). Taoism’s principles of harmony and balance, along with its focus on the flow of energy or qi, also resonate with the integrative aspects of transpersonal psychology, which seeks to unify spiritual and psychological dimensions.

Western mystical and philosophical traditions also played a key role in shaping the foundations of transpersonal psychology. Thinkers such as Plato, Plotinus, and Meister Eckhart contributed to the exploration of metaphysical states and divine connection, emphasizing experiences that go beyond ordinary waking consciousness. Plotinus’ concept of the One and Eckhart’s writings on divine union reflect early articulations of mystical states, which parallel the kinds of spiritual experiences later explored within transpersonal psychology (Stace, 1960). Additionally, the Renaissance and Romantic movements, with their emphasis on human potential, imagination, and the sublime, contributed to a broader cultural interest in transcendent and expansive states of consciousness that informed early transpersonal thinkers.

The perennial philosophy, a term popularized by Aldous Huxley, also served as an important intellectual precursor to transpersonal psychology. This philosophical perspective posits that all major religious and spiritual traditions share a common core of wisdom regarding the nature of reality and the self. Huxley’s work, as well as the writings of other scholars such as René Guénon and Ananda Coomaraswamy, emphasized the universality of spiritual truths across different cultures and eras (Huxley, 1945). The idea of a universal, transcendent reality accessible through spiritual practices and contemplation significantly influenced the development of transpersonal psychology’s framework for understanding human consciousness.

Humanistic Psychology’s Influence

In addition to philosophical and religious traditions, humanistic psychology provided a crucial foundation for the emergence of transpersonal psychology. Humanistic psychology, which emerged in the 1950s and 1960s as a reaction against the deterministic models of behaviorism and psychoanalysis, focused on human potential, self-actualization, and the inherent drive for growth (Bugental, 1964). Pioneers of humanistic psychology, such as Carl Rogers and Abraham Maslow, sought to understand the positive, creative, and growth-oriented aspects of human nature. Maslow’s work, in particular, was instrumental in bridging humanistic and transpersonal psychology, as his concept of peak experiences—a profound sense of connection and transcendence—became a cornerstone of transpersonal inquiry (Maslow, 1964).

Maslow’s hierarchy of needs, which culminates in self-actualization, provided a pathway for understanding the developmental nature of human consciousness. However, Maslow eventually realized that self-actualization did not fully capture the higher states of consciousness that individuals could experience. In response, he coined the term transpersonal to describe experiences that transcend the personal self, including mystical, spiritual, and unitive states of awareness (Maslow, 1969). This recognition of human capacities for spiritual and transcendent experiences expanded the scope of psychological inquiry and laid the groundwork for the formal establishment of transpersonal psychology.

Carl Rogers’ emphasis on the therapeutic relationship and the actualizing tendency in individuals also contributed to the transpersonal movement. While Rogers focused more on the interpersonal and developmental aspects of human growth, his person-centered approach was compatible with transpersonal psychology’s focus on personal transformation and authenticity (Rogers, 1961). Both humanistic and transpersonal psychology share a commitment to understanding the full range of human potential, from personal growth to the spiritual dimensions of existence. As humanistic psychology matured, it became clear that an even broader, more inclusive psychological framework was necessary to fully account for the spiritual and transcendent aspects of human experience, leading to the emergence of transpersonal psychology.

Key Figures: William James and Carl Jung

Among the early psychological thinkers who influenced the development of transpersonal psychology, William James and Carl Jung stand out as foundational figures. William James, often regarded as the father of American psychology, explored religious and mystical experiences as legitimate areas of psychological study in his seminal work, The Varieties of Religious Experience (James, 1902). James argued that mystical experiences provided valuable insights into the nature of consciousness and should be studied scientifically. His concept of “radical empiricism” encouraged an open-minded approach to the study of subjective experience, including altered states of consciousness and spiritual phenomena, which aligned with the later goals of transpersonal psychology (Taylor, 1996).

Carl Jung’s contributions were equally pivotal in shaping the transpersonal perspective. Jung’s theories on the collective unconscious, archetypes, and individuation provided a rich psychological framework for understanding spiritual and transformative experiences. His exploration of alchemy, mythology, and religious symbolism opened new avenues for investigating the deeper layers of the psyche, including those associated with mystical and transcendent experiences (Jung, 1959). Jung’s concept of the Self, which he viewed as the totality of the psyche and a higher aspect of the individual, resonated with transpersonal psychology’s focus on the integration of spiritual and psychological dimensions of the human experience. Additionally, Jung’s interest in synchronicity and his recognition of non-causal, meaningful connections in life events further contributed to the transpersonal exploration of interconnectedness and the nature of reality beyond the ego (Main, 2004).

Jung’s therapeutic approach also paralleled transpersonal psychology’s emphasis on healing and personal transformation through engagement with the unconscious and spiritual aspects of the psyche. His method of active imagination and exploration of dreams as pathways to the deeper layers of consciousness foreshadowed the techniques used in transpersonal psychotherapy. Jung’s holistic approach to the human psyche, which integrated both the individual and collective dimensions of experience, provided a foundational theoretical basis for many transpersonal psychologists seeking to explore the full spectrum of human consciousness and potential (Cortright, 1997).

1960s–1970s: Formal Emergence

The formal establishment of transpersonal psychology as a distinct field occurred in the late 1960s, emerging from the broader movement of humanistic psychology. Abraham Maslow, one of the pioneers of humanistic psychology, was instrumental in the field’s development. After extensively studying self-actualization and peak experiences, Maslow realized that psychology needed a fourth force to explore spiritual and transcendent aspects of human nature (Maslow, 1969). In his work, Maslow noted that the humanistic perspective, while valuable, was limited in its focus on ordinary consciousness and did not fully address experiences that transcend the self, such as mystical or transcendent states. He coined the term “transpersonal” to describe these experiences and advocated for a psychology that acknowledged higher states of consciousness and spiritual dimensions (Grof, 2008).

Maslow’s collaboration with Anthony Sutich, a psychologist deeply interested in spirituality and mystical experiences, marked a turning point in the formalization of transpersonal psychology. Sutich, inspired by Maslow’s work, sought to create a new field that integrated spiritual practices and transcendent experiences into psychological research. Together, they co-founded the Journal of Transpersonal Psychology in 1969, providing a platform for the publication of research and theoretical articles related to transpersonal experiences (Sutich, 1976). The establishment of this journal signified the official recognition of transpersonal psychology as a distinct discipline within the broader psychological community. In the same year, the Association for Transpersonal Psychology (ATP) was formed, creating a professional organization to support the development of the field.

The late 1960s and early 1970s saw transpersonal psychology grow in prominence, attracting a diverse group of scholars, practitioners, and researchers interested in exploring consciousness, spirituality, and human potential. This period was marked by an interdisciplinary approach that combined insights from psychology, philosophy, and spiritual traditions (Vich, 1988). Transpersonal psychology’s emphasis on integrating Eastern spiritual practices such as meditation, as well as indigenous traditions like shamanism, reflected the field’s global and cross-cultural scope. The initial growth of the discipline was fueled by the social and cultural transformations of the 1960s, a period of increased interest in alternative states of consciousness and spiritual exploration.

Initial Reception and Growth

The reception of transpersonal psychology within the broader psychological community was mixed. On one hand, it attracted a cohort of psychologists, therapists, and academics who were disillusioned with the limitations of mainstream psychology’s focus on pathology, behavior, and cognition. These individuals were drawn to the field’s open-minded exploration of consciousness, spirituality, and human transformation (Walsh & Vaughan, 1993). However, the early growth of transpersonal psychology was also met with skepticism, particularly from those in mainstream psychology who questioned the empirical rigor of the field. Critics argued that transpersonal psychology’s focus on subjective experiences—such as mystical states or spiritual awakenings—lacked the scientific grounding required for acceptance within conventional psychological research (Hartelius, Caplan, & Rardin, 2007).

Despite these challenges, transpersonal psychology continued to expand throughout the 1970s, particularly in the realm of psychotherapy. Key figures in the field, such as Stanislav Grof, developed therapeutic approaches that incorporated transpersonal concepts, particularly through the use of altered states of consciousness. Grof’s pioneering work in psychedelic therapy and holotropic breathwork provided a practical application of transpersonal psychology in clinical settings (Grof, 2008). His research on non-ordinary states of consciousness demonstrated the potential for these experiences to facilitate profound psychological healing and transformation, further legitimizing transpersonal psychology’s relevance in therapeutic practice.

During this period, transpersonal psychology also began to establish itself as an academic discipline, with several universities and research institutions offering courses and programs focused on transpersonal studies. The Esalen Institute in California, a hub for humanistic and transpersonal psychology, became a center for workshops and training programs that integrated psychological and spiritual approaches to personal development (Kripal, 2007). These early academic and professional developments helped solidify the field’s foundation and ensured that transpersonal psychology would continue to grow, despite ongoing debates regarding its scientific legitimacy.

The Journal of Transpersonal Psychology and the Association for Transpersonal Psychology

The establishment of the Journal of Transpersonal Psychology in 1969 was a critical milestone in the development of the field, providing a dedicated space for the dissemination of research and theoretical work in transpersonal psychology. The journal, founded by Anthony Sutich, aimed to bring together scholars from various disciplines to explore human consciousness, spiritual experiences, and psychological transformation. Early issues of the journal included articles on topics such as peak experiences, altered states of consciousness, and the integration of Eastern spiritual practices into Western psychology (Sutich, 1976). The journal played a vital role in legitimizing transpersonal psychology by encouraging rigorous scholarly inquiry into these previously marginalized areas of study.

The formation of the Association for Transpersonal Psychology (ATP) in the same year further institutionalized the field. The ATP was established to support the professional development of transpersonal psychologists and to foster collaboration between scholars and practitioners (Vich, 1988). Through conferences, workshops, and professional networks, the ATP provided a forum for the exchange of ideas and the development of new research methodologies tailored to transpersonal topics. The organization also worked to promote the integration of transpersonal principles into psychotherapy, education, and other applied fields, helping to extend the reach of transpersonal psychology beyond academia.

The Journal of Transpersonal Psychology and the ATP became central pillars of the transpersonal movement, contributing to the field’s sustained growth and development. By offering a platform for dialogue and collaboration, they helped create a sense of community among those interested in exploring the transpersonal dimensions of human experience. Over the following decades, both the journal and the ATP continued to play key roles in shaping the trajectory of transpersonal psychology, supporting its expansion into new areas of research and practice while maintaining a commitment to exploring the spiritual and transformative aspects of human nature (Hartelius et al., 2007).

Evolution of Transpersonal Psychology (1980s–1990s)

During the 1980s and 1990s, transpersonal psychology evolved through deeper integration with other disciplines and a growing emphasis on scientific rigor. Researchers in the field began exploring connections with emerging scientific paradigms, such as systems theory, quantum physics, and consciousness studies. The principles of systems theory, which highlight the interconnectivity of all systems, aligned with the transpersonal perspective that human consciousness is interconnected with broader cosmic and ecological systems (Laszlo, 1996). Likewise, the non-locality principles of quantum physics resonated with transpersonal concepts of interconnectedness and unity consciousness, suggesting that consciousness might not be entirely localized in the brain but instead could extend beyond the individual (Capra, 1999). This interdisciplinary collaboration broadened the theoretical foundations of transpersonal psychology, allowing it to transcend traditional psychological boundaries.

A key figure during this period was Ken Wilber, whose Integral Theory provided a comprehensive framework for understanding human consciousness. Wilber’s model integrated insights from psychology, philosophy, and spirituality, proposing that consciousness evolves through various stages, from pre-personal to personal and ultimately to transpersonal (Wilber, 2000). His work was influential in positioning transpersonal psychology as a legitimate field of study that incorporates multiple dimensions of human experience, from biological to spiritual. Wilber’s emphasis on integrating subjective, psychological, and objective perspectives helped bridge the gap between spirituality and science, which was a major challenge for transpersonal psychology in its earlier years. His work also sparked further research on the stages of consciousness and how individuals can achieve higher states of awareness through personal and spiritual growth.

The 1980s and 1990s also saw significant growth in the practical applications of transpersonal psychology, particularly in the fields of therapy and counseling. Researchers and clinicians began to develop and apply transpersonal approaches to psychotherapy, focusing on integrating spiritual experiences into therapeutic practice (Grof, 2008). Techniques like meditation, mindfulness, and holotropic breathwork were employed to help individuals access altered states of consciousness for healing and self-transcendence. Stanislav Grof’s work on holotropic breathwork, which uses controlled breathing to induce non-ordinary states of consciousness, gained traction during this period as a powerful therapeutic tool (Grof, 2000). These practical applications allowed transpersonal psychology to expand its reach beyond academia, offering new therapeutic techniques for addressing trauma, personal growth, and spiritual transformation.

Challenges and Criticisms

Transpersonal psychology, since its inception, has faced significant challenges and criticisms, particularly concerning its scientific legitimacy. One of the primary critiques has been the difficulty in empirically validating the subjective experiences that are central to transpersonal psychology, such as mystical states, spiritual awakenings, and altered states of consciousness. Traditional psychological research often relies on quantitative methods and observable phenomena, whereas transpersonal psychology emphasizes subjective, personal experiences that are difficult to measure using conventional scientific tools (Hartelius, Caplan, & Rardin, 2007). This has led many in mainstream psychology to question the field’s scientific rigor, arguing that it lacks the empirical foundation necessary to be considered a legitimate branch of psychology (Friedman, 2015). The subjective nature of many transpersonal experiences, which are often deeply personal and culturally specific, presents inherent challenges to creating universal standards of measurement and validation.

Another major challenge for transpersonal psychology has been its relationship with mainstream academic psychology. While transpersonal psychology emerged as a “fourth force” in psychology, it has struggled to gain widespread acceptance within academic institutions. The field’s focus on spirituality and mysticism has been viewed by some as incompatible with the more secular and empirical focus of modern psychology. Many universities have been hesitant to incorporate transpersonal psychology into their curricula, fearing that its emphasis on spiritual experiences may conflict with the scientific principles that guide psychological education and research (Taylor, 1999). Moreover, the field’s interdisciplinary nature, which integrates insights from religious studies, philosophy, and metaphysics, has made it difficult for transpersonal psychology to fit neatly within the boundaries of traditional psychological disciplines, further hindering its acceptance in academic circles.

Despite these criticisms, transpersonal psychology has also been challenged from within by debates regarding the appropriate balance between science and spirituality. Some scholars argue that the field needs to further develop its scientific methodologies to better align with mainstream psychology, while others believe that the value of transpersonal psychology lies precisely in its ability to address aspects of human experience that cannot be fully understood through empirical methods alone (Ferrer, 2002). This internal tension between maintaining scientific credibility and preserving the spiritual and transformative essence of the field has been a longstanding challenge for transpersonal psychology. As the field continues to evolve, ongoing efforts to bridge the gap between science and spirituality will likely play a critical role in determining its future direction and impact within the broader psychological community.

Contemporary Transpersonal Psychology (2000–Present)

Since the turn of the millennium, transpersonal psychology has continued to evolve and gain recognition, particularly through its contributions to therapeutic practices, consciousness studies, and interdisciplinary research. One of the key areas where transpersonal psychology has made significant inroads is in the study and application of mindfulness and meditation techniques, which have gained widespread popularity in both clinical and educational settings. Research on mindfulness, grounded in Buddhist practices but increasingly secularized, has demonstrated numerous psychological and physiological benefits, such as reducing stress, improving emotional regulation, and enhancing overall well-being (Kabat-Zinn, 2003). Transpersonal psychology has played a foundational role in promoting mindfulness as a legitimate psychological practice, linking its application to spiritual growth and self-transcendence while also embracing rigorous scientific research to validate its effectiveness (Friedman & Hartelius, 2015).

Another major area of expansion for contemporary transpersonal psychology is its involvement in psychedelic-assisted psychotherapy. Recent studies on the use of psychedelics like psilocybin, LSD, and MDMA in controlled therapeutic settings have shown promising results in treating conditions such as depression, PTSD, and addiction (Carhart-Harris & Goodwin, 2017). These studies resonate deeply with the core principles of transpersonal psychology, which has long been interested in the transformative potential of altered states of consciousness. Stanislav Grof’s early work on the therapeutic use of psychedelics set the stage for this modern resurgence in interest, and transpersonal psychologists continue to contribute to research and discussions about the responsible and ethical use of psychedelics in psychotherapy (Grof, 2008). This revival of interest in psychedelics has brought transpersonal psychology further into the mainstream, bridging the gap between clinical research and spiritual exploration.

In addition to its contributions to therapy and consciousness studies, transpersonal psychology has also become increasingly globalized and interdisciplinary. Researchers and practitioners have been exploring the intersection of transpersonal psychology with environmental psychology, ecological awareness, and global social issues. The field’s emphasis on interconnectedness and the unity of all life has provided a framework for understanding the psychological and spiritual dimensions of environmental crises, such as climate change and ecological degradation (Walsh, 2016). Contemporary transpersonal psychology encourages a holistic approach to these global challenges, advocating for a deeper connection to nature and a spiritual understanding of the human role in the ecological system. This broadening of focus reflects the field’s commitment to addressing not only individual psychological well-being but also collective, planetary concerns in the 21st century.

Conclusion

The history of transpersonal psychology reveals a field that has consistently sought to expand the boundaries of psychological inquiry by integrating spirituality, consciousness, and transformative experiences. From its formal emergence in the late 1960s through the foundational work of pioneers like Abraham Maslow, Stanislav Grof, and Anthony Sutich, transpersonal psychology has addressed dimensions of the human experience that were traditionally neglected by mainstream psychology (Grof, 2008). The field’s development was fueled by interdisciplinary influences, including insights from philosophy, Eastern spirituality, and humanistic psychology. Despite initial skepticism, transpersonal psychology has maintained its relevance by adapting to changing cultural and scientific contexts, consistently advocating for the importance of spiritual and transcendent experiences in psychological growth and well-being (Vich, 1988).

The challenges faced by transpersonal psychology, particularly regarding its scientific legitimacy and acceptance within mainstream academia, remain ongoing. While criticisms about the subjective and non-empirical nature of transpersonal experiences have persisted, the field has responded by developing more rigorous research methodologies and expanding its focus into areas such as mindfulness and psychedelic-assisted therapy. The integration of scientific approaches, such as neuroscience and consciousness studies, has helped bridge the gap between the spiritual and empirical dimensions of human experience, allowing transpersonal psychology to gain greater acceptance and visibility in clinical settings and research (Friedman & Hartelius, 2015).

Looking to the future, transpersonal psychology continues to offer valuable insights into both individual and collective well-being, especially as humanity faces increasing global challenges. Its focus on interconnectedness, unity consciousness, and ecological awareness provides a meaningful framework for addressing issues such as environmental degradation and social fragmentation (Walsh, 2016). As transpersonal psychology evolves, it will likely continue to enrich the broader field of psychology by offering a unique perspective on the full range of human consciousness and potential, fostering personal transformation, spiritual growth, and planetary healing.

Bibliography

1. Bugental, J. F. T. (1964). The third force in psychology. Journal of Humanistic Psychology, 4(1), 19–26. https://doi.org/10.1177/002216786400400102
2. Capra, F. (1999). The Tao of Physics: An Exploration of the Parallels Between Modern Physics and Eastern Mysticism. Shambhala Publications.
3. Carhart-Harris, R. L., & Goodwin, G. M. (2017). The therapeutic potential of psychedelic drugs: Past, present, and future. Neuropsychopharmacology, 42(11), 2105-2113. https://doi.org/10.1038/npp.2017.84
4. Cortright, B. (1997). Psychotherapy and spirit: Theory and practice in transpersonal psychotherapy. SUNY Press.
5. Ferrer, J. N. (2002). Revisioning Transpersonal Theory: A Participatory Vision of Human Spirituality. SUNY Press.
6. Forman, R. K. C. (1998). The innate capacity: Mysticism, psychology, and philosophy. Oxford University Press.
7. Friedman, H. L. (2015). The role of science in transpersonal psychology: The advantages of middle-range theory. The Journal of Transpersonal Psychology, 47(2), 171-192.
8. Friedman, H. L., & Hartelius, G. (2015). The Wiley-Blackwell Handbook of Transpersonal Psychology. John Wiley & Sons.
9. Grof, S. (2000). Psychology of the Future: Lessons from Modern Consciousness Research. SUNY Press.
10. Grof, S. (2008). The adventure of self-discovery: Dimensions of consciousness and new perspectives in psychotherapy and inner exploration. SUNY Press.
11. Hartelius, G., Caplan, M., & Rardin, M. A. (2007). Transpersonal psychology: Defining the past, divining the future. The Humanistic Psychologist, 35(2), 135-160. https://doi.org/10.1080/08873260701274017
12. Huxley, A. (1945). The perennial philosophy. Harper & Brothers.
13. James, W. (1902). The varieties of religious experience: A study in human nature. Longmans, Green, and Co.
14. Jung, C. G. (1959). The archetypes and the collective unconscious (R. F. C. Hull, Trans.). Princeton University Press.
15. Kabat-Zinn, J. (2003). Mindfulness-based interventions in context: Past, present, and future. Clinical Psychology: Science and Practice, 10(2), 144-156. https://doi.org/10.1093/clipsy/bpg016
16. Kripal, J. J. (2007). Esalen: America and the religion of no religion. University of Chicago Press.
17. Laszlo, E. (1996). The Systems View of the World: A Holistic Vision for Our Time. Hampton Press.
18. Main, R. (2004). The rupture of time: Synchronicity and Jung’s critique of modern western culture. Brunner-Routledge.
19. Maslow, A. H. (1964). Religions, values, and peak-experiences. Ohio State University Press.
20. Maslow, A. H. (1969). The farther reaches of human nature. Journal of Transpersonal Psychology, 1(1), 1–9.
21. Maslow, A. H. (1969). Various meanings of transcendence. In J. F. T. Bugental (Ed.), Challenges of humanistic psychology (pp. 93–103). McGraw-Hill.
22. Rogers, C. R. (1961). On becoming a person: A therapist’s view of psychotherapy. Houghton Mifflin.
23. Stace, W. T. (1960). Mysticism and philosophy. Macmillan.
24. Sutich, A. J. (1976). Some considerations regarding transpersonal psychology. The Journal of Transpersonal Psychology, 8(1), 5-13.
25. Taylor, E. I. (1996). William James and transpersonal psychiatry. In S. Boorstein (Ed.), Transpersonal psychotherapy (pp. 21–41). SUNY Press.
26. Taylor, E. I. (1999). Shadow Culture: Psychology and Spirituality in America. Counterpoint.
27. Vich, M. A. (1988). The emergence of the transpersonal orientation: A personal account. The Journal of Transpersonal Psychology, 20(2), 107-120.
28. Walsh, R. (2016). Transpersonal psychology and the ecological crisis. The Journal of Transpersonal Psychology, 48(2), 99-118.
29. Walsh, R., & Vaughan, F. (1993). Paths beyond ego: The transpersonal vision. Tarcher/Putnam.
30. Wilber, K. (2000). Integral Psychology: Consciousness, Spirit, Psychology, Therapy. Shambhala Publications.