The principle of Shiva – Shiva-tattva – is extremely complex. The principle of Brahma is not as complicated, because Lord Brahma is always a jiva, a finite spirit soul. Sometimes, when there is no qualified jiva, Lord Vishnu (Krishna’s expansion) personally takes the post of Brahma, but that is rare. Lord Shiva is not like that; he is not a finite soul. After passing through the eight material coverings, and after crossing the Viraja (the river that divides the material world and the spiritual world) and the planet of Lord Brahma (the highest material planet), one comes to the planet of Shiva. There he is known as Sadashiva, a manifestation of Lord Vishnu.
Shiva-tattva can be understood by the analogy of yogurt and milk. Yogurt is nothing but a transformation of milk. Milk can become yogurt, but yogurt cannot become milk. This analogy is found in Sri Brahma-Samhita and elucidated in Srila Jiva Gosvami’s commentary: “Just as milk is transformed into yogurt by contact with a transforming agent, Sri Govinda, Lord Sri Krishna, similarly accepts the form of Shambhu (Shiva) in order to accomplish a specific purpose. The example of yogurt is actually given in order to convey the idea of cause and effect, not the idea of transformation. Sri Krishna is reality and cannot be transformed, so it is not possible for Him to undergo any kind of distortion. A wish-fulfilling gem manifests many things according to one’s desire, yet its constitutional nature remains untransformed. -Sri Srimad Bhaktivedanta Narayana Maharaja
