The intersection of Western esotericism and Eastern religions examines the historical and conceptual connections between Western mystical traditions and the spiritual and philosophical systems of Asia, including Hinduism, Buddhism, Taoism, and others. This exchange involves doctrines, symbols, and practices, evolving from early interpretations to modern spiritual and wellness trends.

Throughout the 19th and 20th centuries, this interaction led to various movements and syntheses, such as the Theosophical Society, New Thought, and occultist groups like the Ordo Templi Orientis. Later developments included the influence of Eastern philosophies on Carl Jung's psychology, the Traditionalist School's metaphysics, and the rise of universalist spirituality. The academic study of Western esotericism itself emerged partly from this dialogue, seeking to distinguish historical scholarship from the syncretic narratives of modern spiritual movements.

Academically, Western esotericism is defined as a field studying "rejected knowledge" within Western culture, encompassing traditions like Hermeticism, Kabbalah, and alchemy, characterized by concepts like correspondences and inner experience. Eastern religions, in this context, refers to Asian traditions like Hinduism and Buddhism, particularly those aspects assimilated into Western esoteric thought. The study focuses on how these traditions were historically appropriated and reinterpreted, moving from universalist theories to a critical analysis of transculturation and globalization.

The academic field of Western esotericism investigates currents within Western culture traditionally seen as "rejected knowledge," such as Hermeticism, Neoplatonism, and alchemy. These traditions are often characterized by features like correspondences, living nature, and the pursuit of gnosis through inner experience. "Eastern religions," in the context of this exchange, typically refers to specific elements of South, East, and Southeast Asian thought—like Vedanta, Yoga, Tantra, Zen Buddhism, and Taoist alchemy—that have been incorporated and reinterpreted within Western esoteric frameworks. It's important to distinguish this reception from "Orientalism," the discourse through which European intellectuals historically represented the East, often in idealized ways. The focus is on the actual engagement and reinterpretation of Asian religious practices and symbols by Western esotericists for philosophical synthesis and spiritual authority.

Early academic and popular approaches to the Western esotericism and Eastern religions connection often used universalist models, suggesting a shared underlying truth across all religions. Figures like H.P. Blavatsky and Aldous Huxley posited a "perennial wisdom" that tended to blur historical distinctions. Later scholars identified this tendency as "religionism." A significant historical precursor is "Platonic Orientalism," a view originating in antiquity and revived during the Renaissance, which saw Platonic and Hermetic traditions as receiving salvific wisdom from an ancient "East." This perspective allowed 19th-century esotericists to frame Eastern materials as evidence for a primordial truth.

The systematic historical study of Western esotericism emerged as a counterpoint to these universalist views, aiming to define esotericism as a distinct historical field rather than a timeless wisdom tradition. Antoine Faivre's typological model provided a widely accepted academic definition based on structural features. Wouter J. Hanegraaff framed esotericism as "rejected knowledge" within Western culture. The institutionalization of this field in academia, particularly in France and the Netherlands, solidified its status as an autonomous area of research. More recent scholarship has emphasized the discursive, sociocultural, and global dimensions of esotericism, advocating for an integration into a global history of religions that moves beyond a strict Western/Eastern dichotomy.

In the mid-18th century, a specific intellectual environment in Europe fostered a receptiveness to Indic and Sinic models of subtle bodies and energetic cosmologies, which became prominent a century later. This receptiveness was influenced by two interconnected developments. Firstly, vitalist biology, which emerged from medical schools and German Naturphilosophie, emphasized organismic life and viewed the cosmos as imbued with formative forces and micro-macrocosmic correspondences, challenging mechanistic explanations. Secondly, new experimental methods began to "medicalize the supernatural," treating phenomena like trance and clairvoyance as subjects for clinical observation and naturalistic explanation. Within this context, existing Western concepts of subtle embodiment, drawn from Hermetic-Neoplatonic and Paracelsian traditions, were reinterpreted and consolidated. This led to the development of a modern "astral cosmology" and "astral anatomy," using new terminology to describe subtle vehicles.