"Be gracious unto us, O Rudra, bring us bliss!" (Rig Ved, I.114.2).
Out of 6 main Shaiv Sampradaaya five are Aagamik and only one is Vaidik. This one
is Paashupat Shaivism (see GV Tagare, "Shaivism: Some Glimpses", Delhi,
1996, p. 3). Pashupatism is the earliest Hindu cult that has survived till present
Worship of Shiv (as Bhava, Rudra or Pashupati) was already prominent in Vaidik times.
Rig Ved (I.43.5) calls Rudra "luminous like the Sun, gratifying like gold,
best among the Gods".
The famous Mrityunjaya Mantra of Shiv occurs both in Rig Ved ( VII.59.12) and Yajur Ved.
The great Panchaksharee Mantra of Shiv, appears already in Yajur Ved, in a Rudra
Adhyaaya section of Taittireeya Samhita (IV.5.7) and Shata Rudreeya of Vaajsaneyee
Sanhitaa (Ch. 16, 18).
Five Mantra of Shiv, corresponding to five letters of Panchaaksharee, are found in
Taittireeya Aaranyak (17.1-5).
Sayaanaachaarya, a famous Rig Ved commentator, regards that the first words of
these Mantra are the names of Shiv's five faces. Parts of these five Mantra were
taken by Lakulisha (in 100 BC), a Paashupat Shaiv teacher and reformer, into his
Paashupat Sootra (1.40-44).
Rudra is identified with Indra and Agni, main deities of Rig Ved: Maitreyanee
Sanhitaa of Saam Ved (II.1.10) and Shatapath Braahman of Yajur Ved (VI.1.3.10)
say Agnirvai Rudrah, while Rig Ved (II.33.3 ) and Atharv Ved ( IV.28.3; II.2.7;
X.1.23) describe Him as a 1,000-eyed God, a holder of Vajra and a killer or Vritra,
Ved identify Rudra with Rig Vaidik (X.90) primal Purush : Taittireeya Aaranyak (X.14 )
calls Purush as Bhootaanaamaadhipati, ie Rudra; Yajur Ved (Taittireeya-Sanhitaa, IV.5.1)
describes Him in a same manner as a Viraat Purush, and same is repeated in Shwetaashwatar
Upanishad (which belongs to Taittireeya Braahman). Sayaanaachaarya while commenting upon
the verse IV.28.1 of Atharv Ved, tells us that the Lord is called Bhav for having everything
coming out of His body, and that He is called Sharv, because of His destructive character
at the time of dissolution.
Shatapath Braahman (VI.1.3.17) says that Eeshaan, the highest form of Rudra, is same
as Aaditya. Shwetawshwatar Upanishad clearly describes Rudra as the Supreme God, Maheshwar
(IV.10), Purush of Rig Ved and Vishwakarmaa who is seated in the hearts of all human beings
(IV.17). Thus, Rig Vaidik Vishwakarmaa Daivat hymn (X.81) also describes Rudra and no other
god. Rudra is identical to Som, who was worshipped in a pillar, very similarly to Shiv Ling
Maandookya Upanishad (verse 7) names the fourth, the highest Pad of Brahm, as Shiv.
Mahaabhaarat mentions Krishn's initiation into Pashupatism (Anushaasan Parv, 14.379-380).
In the same chapter Yaagyavalkya and Ved Vyaas are said to have been Pashupat Shaiv.
Gautam and Kanada, founders of Nyaaya and Vaisheshikaa schools respectively, were also Paashupat
(see RK Siddhant Shastri, "Saivism Through the Ages", Delhi, 1975, p. 99).
To conclude with, Shaivism is essentially a Vaidik religion (as Pashupatism), which later
got developed with the independent Aagamik revelation. This Aagamik revelation is considered
to be the essence of Ved.
In Bhairav Aagam's Shaivism takes a Shaakt form, but this Aagamik Shaaktism has its root
in Ved again. Shaakt Aagam view Vaidik Agni (who is said to be all Gods together: (Aitareya
Braahman, II.6.3) as Devee, Durgaa, Bhairavee or Kundalinee. Durgaa is invoked with Vaidik
Rik (I.99.1) connected with Agni. In Devee Upanishad, also known as Devya Atharvaa Sheersh
(verse 9), Durga is called Agni Varnaa and Tapas Jwalantee.
As Agni and Som of Ved are invoked in pair, for example, in Rig Veda, I.93), or Agni
and Indra similarly come in pair: (Rig Ved, I.21), in the same way are Shakti and
Shiv of Tantra. They also come in pair. Bhaaskar Raaya in Lalitaa Sahastra Naam
Bhaashya (Name 407) quotes Shruti: "One Rudra is hidden in all beings, he is
with Maayaa, with parts and without parts. He is Devee herself, and is not separated
from her. By knowing this, one attains immortality."
Supreme Shakti of Tantra was known in Vaidik times as Aditi, mother of gods, and her
manifestations were Saraswatee, Ushaa(s) (Face of Aditi - Rig Ved, I.113.19) and alike.
Rig Ved (I.89.10) says: "Aditi is Heaven, Aditi is Mid-region, Aditi is Mother
(Earth), Father and Son. She is all the Gods; she is the Five peoples. Aditi is all
that is born and what is to be." In Rig Vaidik Devee Sookt ( X.125.3-4) the Goddess
says: "The Queen, I am the dispenser of wealth; conscious, I am the first among
the Gods… They that ignore me run to ruin."
Ken Upanishad (which belongs to Tandya or
Jaimini Braahman of Saam Ved) shows Umaa revealing the knowledge of Brahm to the gods
(according to Mahaa Vashishth, "Umaa is so called because it contains the essence
of the Pranav").
In Muktikaa canon (Upanishad) there
are eight Upanishad devoted specifically to Shakti: Bahvricha, Bhaavanaa, Devee, Saubhagya
Lakshmee, Saavitree, Seetaa, Tripuraa, Tripurataapinee.
The worship of Shakti as the Yoni has also got Vaidik roots:
Aitareya Braahman ( II.6.3) says that "Agni is the womb of the Gods";
Shwetaashwatar Upanishad (V.5) calls Rudra as "Yoni"; and
Brihadaaranyak Upanishad (Kanv VI.4.2) refers to worship of women's Yoni by Prajapati.
Both Brihadaaranyak (Kanv VI.4.3; VI.2.13) and Chhaandogya (II.13.1-2) view sexual
act as holy practice.
Taantrik doctrine of divine nature of women also finds support in Vaidik Shruti
(Brihadaaranyak, Kanv III.9.11).