The Vedic literature refers to a minor atmospheric deity, with fearsome powers called Rudra.
Gavin Flood states that it is not clear from the seal that the figure has three faces, is seated in a yoga posture, or even that the shape is intended to represent a human figure.
The Shiva in Kushan coins is referred to as Oesho of unclear etymology and origins, but the simultaneous presence of Indra and Shiva in the Kushan era artwork suggest that they were revered deities by the start of the Kushan Empire.
For example, in the Jain caves at Ellora, extensive carvings show dancing Indra next to the images of Tirthankaras in a manner similar to Shiva Nataraja.
Dualistic Shaiva Agamas which consider soul within each living being and Shiva as two separate realities (dualism, dvaita), are the foundational texts for Shaiva Siddhanta.
The monist Shiva literature posit absolute oneness, that is Shiva is within every man and woman, Shiva is within every living being, Shiva is present everywhere in the world including all non-living being, and there is no spiritual difference between life, matter, man and Shiva.Shaivism is one of the four major sects of Hinduism, the others being Vaishnavism, Shaktism and the Smarta Tradition.