“What causes this change?
For any activity the causes are usually two or three:
– Nimitta – Efficient cause (i.e. weaver, potter)
– Upadāna – Material cause (i.e. threads, dye, clay)
– Kāraṇa – Accessories (i.e. loom, wheel)
It is possible without the third.
Vedānta attributes the first two to Brahman. Like a spider producing from itself a web to spin a web.
However according to Yoga, transformation from one being to another at the end of one Janma is not due to the presence of Brahman.Then how does it take place?
The farmer is diverting the water in a particular direction by merely removing obstacles.
The Prakṛti flows by itself to go to a higher or lower to have more Sattva or Tamas. All we can do is keep removing the bunds.
The Prakṛti flows by itself.
This analogy can be applied to manifestations of Prakṛti  within the individual.
In Prāṇāyāma when we remove the obstacles the Prāṇa flows by itself.
With regards to the Nāḍī when the Granthi are pierced Kuṇḍalinī flows by itself.
Nimitta here usually means Dharma or Sattva and Adharma or Tamas.
Right action of wrong action are not caused they don’t create something new. The flow is the Guṇa or Prakṛti  and depending where the flow is opened or closed comes Sattva or Tamas.
Puruṣa nor Īśvara have no part in this process at all.
However this is still within the realms of transformation and is thus only a temporary state.”