When the Agamas want to show the whole of Shiva's work at once, they give him five faces. Each looks in a direction and does one thing: the western face brings things into being, the northern keeps them, the southern ends them, the eastern hides the truth from souls not ready for it, and the upward face, Ishana, lifts the veil in grace. Ten arms reach into the ten directions. Shaiva Siddhanta names the five works the Panchakritya and says Shiva performs them as Sadashiva while remaining the efficient, not the material, cause of the world; Kashmir's non-dual school places Sadashiva third in its ladder of thirty-six principles, after Shiva and Shakti.
In the sanctum at Pashupatinath a stone linga about a metre high carries four faces: Tatpurusha to the east, Aghora to the south, Sadyojata to the west, Vamadeva to the north. The fifth face, Ishana, has no carving; the tradition says it looks upward and is to be imagined, the dimension the eye cannot reach. Only the temple's four Bhatta priests may touch the image.
What is different here:
Four faces carved, the fifth left unseen; a living cult image rather than a textual scheme.
The best-known image of this idea is the seven-metre bust cut into the back wall of Elephanta's main cave in the fifth or sixth century. Three faces are visible: a fierce one with a moustache and serpent, a calm central one, and a soft, almost feminine one. Visitors call it the Trimurti, but art historians read it as Sadashiva with two faces hidden in the rock, and they label the visible three variously as Aghora or Bhairava, Tatpurusha, and Vamadeva or Uma.
What is different here:
Three faces shown of five; scholars disagree on the labels; the 'Trimurti' name is popular usage, not the sculptors' programme.