The Ekātmavādī philosophy has emerged from the Upaniṣadic beliefs. There is only one soul. Ekātmavāda- this concept is presented in Sūtrakṛtāṅga's first skandha. As a lump of clay appears in different forms, similarly, the whole world is the product of a singularity and it appears in different forms.[1]
The commentator explains this fact by stating that as the same lump of clay is the base of a river or an ocean or a mountain or a city or a town etc. and appears in different forms, so, in the same manner, the whole conscious and non-conscious world is the product of one supreme consciousness. It implies that only a single soul possesses knowledge and appears in various forms, like, the earth and other elements.[2]
In the Niryukti of Sūtrakṛtāṅga, this theory has been called 'ekappaye[3]'ekātmavāda'. The commentators have referred to it as 'ātmādvaitavāda'.[4] It is not been presented any special philosophical theory, but the examples presented in the commentary are related to the Upaniṣad literature.[5], so it can be called as Upaniṣad philosophy. Acārya Mahapragya has considered this opinion of Upaniṣad philosophy. Aitareya Upaniṣad says that previously this world was only a single soul.[6] By clarifying this opinion it says that 'Sat (existence) is one' - this philosophy is found in Ṛgveda (1/164/46). But that 'sat' was not in the form of soul.
In Chāndogya Upaniṣad[7], it has been mentioned that only by knowing one lump of clay, we can know all the clay-made things. All the other forms are distorted forms of clay ultimately; the clay is real.[8]
According to Jain philosophy, one soul or supreme consciousness is not real. There is no single soul who is the original cause of this visible world. Souls are infinite. They have their independent existence. Each soul has its own consciousness.[9]
'ege āyā'[10], this statement is available in Sthānāṅga, which means soul is one. However, its meaning is not to express the Ekātmavāda accepted as in the Upaniṣads. This statement is presented, only from a synthetic point of view.