The Lord says, “Oh Mother, I am going to tell you the signs and implications of Thathwam. The man who desires Mukthi shall know the Thathwam and thus knows that the body, senses and Anthakarana (inner faculties) belong to nature. When he knows that body and its faculties belong to nature and the Self has no attachment with them, then the body consciousness will vanish. Thus “Jeeva Thathwa” will become pure and you will attain Mukthi from the cycle of births and deaths. So, knowing Thathwam is most essential for attaining Mukthi.

I will give that Knowledge which will remove the “I”ness in you. When you know the Thathwam, you will realize the Self that is separate from them”

Then the Lord defines Purusha as, “the chaitanyam that is omnipresent every where is Purusha or the Self. Body (“Jadam” or the mortal thing) belongs to nature”.

Sankhya deals with the trinity of “Jeevan, Easwaran and Jagath”.

Note – this part of Srimad Bhagavatham (3rd canto, 26th chapter) is giving such solid and precise definitions of very deep Knowledge.