• The author critiques certain claims of Vajrayāna and shows how Vajrayāna is not sui generis. It should be kept in mind that this is an excerpt from a ‘in-the-works’  unfinished manuscript and is in no way exhaustive. Citations and footnotes are removed for this online format here.

Introduction: The Primacy of the Āgamic Revelation

This analysis argues that Vajrayāna Buddhism, far from being a unique or supreme “vehicle” to enlightenment, is a philosophically strained and historically dependent system that reinterprets and selectively appropriates core principles of Tantra. 

The authentic tantric path, as revealed in the Hindu Āgamas and perfected in Śākta traditions, is founded on a metaphysics of affirmative non‑dualism: the recognition of the world as the real, conscious, and blissful expression of the Divine. Vajrayāna’s foundation in the negative doctrine of Śūnyatā (emptiness) departs from this life‑affirming vision and represents a scholastic attempt to graft tantric methods onto a soteriological framework that is inherently world‑negating.

This assessment proceeds in three parts.

Part I demonstrates the philosophical chasm between Śākta realism and Buddhist phenomenalism.

Part II adduces textual, historical, and iconographic evidence to show Vajrayāna’s substantial adaptation of its core tenets from Śaiva–Śākta sources. 

Part III examines key Vajrayāna rituals and practices, suggesting that many are as later, often symbolic, reinterpretations of their more robust Hindu antecedents.

The conclusion is clear: Vajrayāna is not an independent tantric revelation but a Buddhist scholastic appropriation of an older and more philosophically coherent system of Hindu Tantra, as codified in the Āgamas. Its claims to originality—particularly its reliance on a primordial Buddha such as Vajradhara as the source of its tantras—are historically untenable myths designed to obscure a profound debt to the Śaiva–Śākta Āgamas.

Part I. The Philosophical Distance: Pūrṇatva versus Śūnyatā

The fundamental incompatibility between Hindu Śākta Tantra and Buddhist Vajrayāna lies not in their methods, which can be strikingly similar, but in their foundational metaphysics.

Śākta Tantra is a path of radical affirmation, grounded in the ultimate reality of a conscious, blissful, and substantive Absolute. Vajrayāna, by contrast, inherits the Mahāyāna Buddhist doctrine of Śūnyatā, a philosophy of negation that denies the ultimate existence of any such substance. The adoption of tantric techniques within Vajrayāna thus attempts to divinize a cosmos that its own core philosophy deems empty and illusory.

The Metaphysics of Affirmation: Śākta Non‑dualism and the Reality of the Cosmos

Śākta Tantra teaches a non‑dual (advaita) reality that diverges sharply from the illusionism of Śaṅkara’s Advaita Vedānta. In the Śākta worldview, the static, conscious principle-Śiva or Brahman—is eternally and inseparably one with its dynamic, creative energy, Śakti.

Śakti is not an illusory power (māyā) that veils a distant, inactive Brahman; she is Brahman in its active, manifest state. The world is not an illusion (mithyā) to be transcended but is the very body and play (līlā) of the Divine Mother. As the Devī Upaniṣad declares, the Goddess is “essentially Brahman.” This theology is one of pūrṇatva (“fullness”), wherein every facet of existence—from the highest spiritual planes to gross matter, including the human body with its passions and limitations—is a real, vibrant manifestation of the Divine.

In this affirmative vision, Brahman is a positive, substantive, and eternal reality (satya), the uncaused cause that is the source, support, and final destination of the cosmos. The universe emanates from Śakti and dissolves back into her in great cosmic cycles, a ceaseless process of divine self‑expression. Because the world is real and divine, engagement with it through the body, the senses, and ritual action is not bondage but a direct means of liberation.

The Soteriology of Negation: Vajrayāna’s Foundation in Śūnyatā

Despite its elaborate ritualism, Vajrayāna rests on the philosophical foundations of Mahāyāna Buddhism, specifically the Madhyamaka doctrine of Śūnyatā. This is a theology of absence, not fullness. Śūnyatā maintains that all phenomena—from a stone to a Buddha—are “empty” of inherent, independent, or essential nature (svabhāva); an apophatic, negative method negates every attempt to posit a substantive reality.

Śūnyatā is thus the antithesis of Śākta pūrṇatva. Where Brahman is self‑existent, eternal, and substantive, Śūnyatā denies any such ground. As Nāgārjuna insisted, there is an “emptiness of emptiness”: emptiness itself is not a transcendental ground but a description of dependently arisen phenomena. 

From a Śākta standpoint, this tends toward a non‑substantialist stance that many critics read as quasi‑nihilistic and renders the tantric project incoherent. Tantra’s power derives from the premise that the world is real and divine; thus, engagement with its energies is a valid path to liberation. Vajrayāna nonetheless applies these world‑affirming methods to a reality its own philosophy deems illusory and non‑substantial. 

The result is a persistent tension: one seeks enlightenment by visualizing and uniting with deities and universal forces that, by one’s own doctrinal lights, are fundamentally empty. Practices of deity‑yoga, maṇḍala visualization, and subtle‑body manipulation are thereby directed toward realizing the divinity of what is ultimately a void—a palace raised on an ontological premise of non‑substantiality.

The Constructed Union: Deconstructing Emptiness (Śūnyatā) and Compassion (Karuṇā)

To accommodate tantric emphases on union, Vajrayāna posits a central dyad: the union of Wisdom (prajñā), defined as the realization of Śūnyatā, and Method (upāya), expressed primarily as universal Compassion (karuṇā). This union is symbolized by the sexual embrace of male and female deities (yab‑yum). From a Śākta perspective, the dyad is a scholastic construct—an attempt to solve a doctrinal problem of Buddhism’s own making.

2 In Ladakh Monastery. L to R Manjushree (deity of wisdom), Avalokiteshwara (Compassion) and Vajrapana (represents wrathful deities).

The Śākta union of Śiva and Śakti is organic and ontological; it names the inseparable, non‑dual reality of pure consciousness (Śiva) and its inherent power, energy, and bliss (Śakti). Creation, manifestation, and salvific action are spontaneous expressions of this single divine reality. There is no need to “add” a principle of action or compassion to a static Absolute; the Absolute is inherently dynamic.

By rejecting a substantive Absolute like Brahman or Śiva, Buddhist philosophy was left with a purely negative ultimate (Śūnyatā) and a separate ethical path (the Bodhisattva’s compassion). To adopt psycho‑sexual techniques predicated on the union of polarities, it reverse‑engineered a dyad: Śūnyatā was mapped to the feminine principle of wisdom, and karuṇā to the masculine principle of method. This pairing is functional rather than ontological; it joins a philosophical view to a practical imperative. In a universe fundamentally devoid of a substantive self (anātman), the basis for genuine universal compassion becomes philosophically tenuous. The yab‑yum is thus an intellectual contrivance, whereas the Śaiva–Śākta union describes cosmological reality itself.

Part II. The Unacknowledged Debt: Historical and Textual Derivations

Vajrayāna’s philosophical tension is compounded by the historical record, which shows a heavy dependence on Hindu Tantra. Rather than an independent revelation, Vajrayāna appears as a latecomer that systematically appropriated structures, deities, and practices from the pre‑existing and culturally dominant Śaiva–Śākta traditions of medieval India. Its claims to unique origins are not well supported by textual and archaeological evidence and point instead to a clear, one‑way flow of influence.

The Śaiva Matrix: Alexis Sanderson’s The Śaiva Age and a Borrowing Model

Alexis Sanderson’s long essay The Śaiva Age: The Rise and Dominance of Śaivism during the Early Medieval Period advances a carefully argued borrowing model that moves beyond vague appeals to a “shared cultic stock” and demonstrates substantial, often verbatim adaptation of Śaiva–Śākta ritual systems, iconography, and passages—especially from the Vidyāpīṭha and Kaula streams—into the Buddhist Yoginītantras. He situates this process in what he calls the “Śaiva Age” (approximately the sixth to thirteenth centuries CE), when Śaivism, supported by royal patronage and popular cults, was the subcontinent’s dominant religious force.

The evidence is textual as well as circumstantial. The Buddhist Cakrasaṃvara Tantra and Hevajra Tantra contain extensive passages traceable to Śaiva sources such as the Picumata–Brahmayāmalatantra and the Tantrasadbhāva. The Guhyagarbha Tantra, foundational for the Nyingma school, exhibits clear structural and conceptual parallels with Śaiva tantras. Sanderson notes that the Buddhist versions at times display grammatical irregularities or misreadings of the Śaiva originals, confirming their secondary character. The claim of a secret transmission from a celestial Buddha like Vajradhara functions as a revisionist strategy to legitimize appropriation by positing a superior esoteric source. The much‑vaunted secrecy of Vajrayāna thus serves to obscure its unacknowledged debt.

The Pantheon Rearticulated: From Yoginīs and Mātṛkās to Ḍākinīs

The Vajrayāna pantheon of fierce feminine deities, the Ḍākinīs, is not a uniquely Buddhist innovation but a rearticulation of the Yoginīs and Mātṛkās of Hindu Tantra. In Hindu contexts these beings attend major deities, haunt charnel grounds, and bestow siddhis. The very term ḍākinī appears in Purāṇic and Tantric literature as a class of fierce, flesh‑eating attendants of Kālī.

This adaptation extends to male figures. Vajrayāna maṇḍalas frequently depict major Hindu gods—Śiva (as Bhairava), Indra, Brahmā—trampled underfoot by Buddhist deities such as Vajrayoginī or Heruka. Ritual subjugation presupposes a rival power worth conquering; the iconography tacitly acknowledges the Śaiva source while asserting Buddhist dominance through symbolic conversion.

The Subtle Body: A Hindu Blueprint

The esoteric anatomy of the subtle body—energy channels (nāḍīs) and psychic centres (cakras)—is central to all tantric systems. 

Research locates this model in pre‑Buddhist Hindu sources: the Vedas, early Upaniṣads, and later Āgamas and Tantras. The chakra systems of Buddhist tantras (for example, the four‑ or five‑chakra arrangements in the Hevajra Tantra) are later and often simplified relative to the more complex seven‑chakra system codified in Hindu sources such as the Kubjikāmatatantra . Key terminology for the central channels—iḍā, piṅgalā, suṣumnā—and the coiled serpentine energy at the spine’s base, Kuṇḍalinī, are adopted directly; Kuṇḍalinī is rebranded as caṇḍālī or “inner fire” in Buddhist texts. 

Part III. The Ritual Echo: Vajrayāna Praxis as a Reinterpretation of Śākta Rites

Vajrayāna’s adaptive character appears equally in ritual. Many of its signature rites are later, often symbolic, internalizations of originally literal and physically enacted Śākta practices. The shift from the literal to the symbolic is less a spiritual refinement than a philosophical accommodation—an attempt to reconcile world‑affirming methods with world‑negating premises.

The Charnel Ground and the Skull‑Bearer: The Kāpalika Legacy

The aesthetic and ritual complex of Vajrayāna’s wrathful deities descends from the Kāpalikas, radical Śaiva ascetics devoted to Śiva–Bhairava. The Kāpalika vrata involved dwelling in cremation grounds, smearing the body with human ash, and using a human skull (kapāla) as ritual vessel and begging bowl—acts intended to shatter conventional identity and force a direct union with Bhairava.

Vajrayāna absorbed this complex but transformed it largely into a symbolic system:

Wrathful iconography. Herukas and Ḍākinīs adorned with bone ornaments and skull garlands in charnel‑ground settings mirror the Kāpalika ascetic.

Chöd practice. The Tibetan rite of Chöd (“cutting”) internalizes Kāpalika themes by visualizing the offering of one’s own body for dismemberment and consumption by deities and demons in a charnel ground; the same implements (thigh‑bone trumpet, skull‑drum) are used, but the encounter with death and impurity is reframed as a psychological exercise .

Ritual implements. The kapāla (skull‑cup) and kartika (curved knife) become central implements whose meanings are reinterpreted: the skull‑cup symbolizes wisdom realizing emptiness, and the knife the cutting of ignorance, rather than their visceral Kāpalika functions.

The Feast of the Circle: From Cakra‑pūjā to Gaṇacakra

Vajrayāna’s communal rite, the gaṇacakra (“assembly‑circle”), descends from the Śākta Vāmācāra (“left‑hand path”) rite of cakra‑pūjā (“circle‑worship”). The Hindu source rite employs the pañcamakāra (“Five Ms”): wine (madya), meat (māṃsa), fish (matsya), parched grain (mudrā), and sexual union (maithuna). Transgressions forbidden in orthodox Brahmanism were ritually harnessed to transmute poison into nectar and channel worldly energies upward.

In most Tibetan Buddhist contexts this rite is domesticated. The “Five Ms” are replaced with symbolic substitutes: blessed tea or alcohol stands in for nectar, and specially prepared cakes (torma) for flesh; sexual union is transposed into an internal visualization of the union of method/compassion and wisdom/emptiness.

Where Śākta Tantra engages matter as divine, Vajrayāna, treating matter as empty and illusory, relocates engagement to the mind.

The Maṇḍala: From Āgamic Cosmos to Buddhist Palace

The primary ritual diagram of Tantra also reveals adaptation. The term maṇḍala has pre‑Buddhist Vedic antecedents as a cosmic diagram. 

In the Hindu Āgamas and Tantras, the key diagram is the yantra—a minimalist, geometric map of cosmic force and the deity’s energetic body. The Vajrayāna maṇḍala adopts the yantra’s foundational geometry—a central bindu within concentric circles and a square enclosure with four gates—but elaborates it into a pictorial celestial palace populated by a vast pantheon. This marks a shift away from direct, intuitive engagement with pure energy (as in the yantra) toward a more scholastic, memory‑based visualization technology (bhāvanā), as Tantra was absorbed into monastic universities such as Nālandā.

Conclusion: Reassessing Originality and Affirming the Source

On philosophical, historical, and practical grounds, the Vajrayāna conception of Tantra appears historically dependent and rests upon a deep tension. Philosophically, its reliance on the negative principle of Śūnyatā runs counter to the affirmative, world‑embracing spirit of authentic Tantra rooted in Śākta non‑dualism. 

Historically, the record shows wholesale borrowing—from texts and deities to ritual structures and esoteric anatomy—from older and more culturally dominant Śaiva–Śākta traditions, while appeals to a primordial Buddha such as Vajradhara function as legitimating myths. Practically, signature rites—from Chöd and the gaṇacakra to the elaborated maṇḍala—are symbolic internalizations or scholastic elaborations of older, more literal Śākta rites.

Vajrayāna is therefore not the “Diamond Vehicle,” the supreme and swiftest path, but an echo: a Buddhist re‑reading of a more ancient and powerful revelation. The true adamantine vehicle is the Śākta path that recognizes the indestructible, vajra‑like reality of the divine cosmos and provides means to realize oneself as a participant in its blissful, conscious play. To seek the source of Tantra, one looks not to the scholastic creations of Buddhist vihāras, but to the primordial revelation of the Hindu Āgamas and the living embodiment of that truth in the Divine Mother, Śakti.

Notes: This is a part of a larger book length project where the citations will be provided. This is by no means exhaustive. Further, this should be treated as a working draft, rather than a polished final manuscript’s part. 

The author is a comparative theologian.

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