An important chapter in the spiritual history of India is the development of a line of spiritual discipline called Tantra. These Tantra Shastras are usually dated in the first millennium after Christ. Traditionally it is the scripture of the common man, open to all persons, without any restrictions of caste or scholarship. Tantra in Sanskrit has many meanings. As Sri Kapali Sastry points out, the relevant meaning of the word Tantra is “to act”. Thus ritual — ritual is an act — is a characteristic common to all the Tantrik disciplines. The connection between the Veda and Tantra will be discussed.
It is not uncommon to find in some books on the history of India a statement that Tantra Shastra developed as a rebellion against the Vedas since the latter was theoretically accessible only to members of the two higher castes. The latter statement is not even loosely true since the Chandogya Upanishad indicates that the Vedas were taught to any student with sincere aspiration regardless of caste. Even otherwise, Tantra Shastra holds the Vedas in high regard and quotations from the Rig Veda are used in Tantra Shastra to support its approach. While the Upanishads represent an attempt at recovering the jnana or knowledge portions of the Vedas, the Brahmanas represent an attempt at reinforcing the ritual aspect of the Vedas, the Tantra Sastra represents an attempt at preserving and expanding the esoteric or the occult part of the Veda. A quotation from Sri Aurobindo is very appropriate: «The mental images of the Vedic gods in the mantras of Rig Veda (were replaced) by mental forms of the two great deities, Vishnu and Shiva, and their Shaktis and by corresponding physical images which are made the basis both for external worship and for the Mantras of inward adoration and meditation, while the psychic and spiritual experience which the inner sense of the Vedic hymns expresses finally disappeared into the psycho-spiritual experience of the Puranic and Tantrik religion and yoga» (On the Veda).
First let us consider the gods in the Tantra and the gods in the Vedas. There is almost a one-to-one correspondence between the gods in the two scriptures, not only in the outward description of their powers, but also in their spiritual import. In the Tantra, as in the Vedas, we find the recognition of one Supreme Deity as the highest along with the simultaneous adoration of a number of other deities. The Tantric gods, like the Vedic gods, have a twofold aspect: in their external aspects they are the powers of physical nature like rain, wind, etc. But, in their more important esoteric aspects, they represent psychological and psychic movements. For example, Agni of the Veda continues in the Tantra as Kumara, the child of the lord Shiva. In Veda, Agni is in the forefront of gods, their guide and messenger. In the Tantra, Kumara is the commander-in-chief of the gods and is looked up to for his immense store of knowledge and wisdom by the seers of later times. The role of Indra in the Veda is taken over in Tantra, by Rudra who brooks no obstacle. The Sun, the highest God of the Veda, is addressed in the Tantra as Vishnu, a name used in the Veda itself. The role of the Aditi of the Veda is represented by the Supreme Shakti, called as Uma, Gouri, etc. It is true that there are new gods in the Tantra, but the prominent gods of the Veda retain their supremacy under different names and forms.
The Tantra, like the Veda, places a high emphasis on the Mantra. A mantra is not a mere letter or collection of letters with some meaning «it is the sound-body of a Power charged with the intense vibrations of the spiritual personality of the creator or seer of the Mantra. When a mantra is uttered under proper conditions, it is not the feeble voice of the reciter that goes forth to evoke the response of the gods to whom it is addressed, but the flame of tapasya (askesis) and realization that is lying coiled up in the body of that utterance. The Tantra, following the Veda, has formulated some seed-letters, bijakshara, which the seeker uses as the Mantra. These Bijaksharas have been endowed with a perennial store of power by the Tantrik seers and it needs only the living touch of the Guru to set them awake in the disciple» (Kapali Shastry).