15.17 But there is the 'Supreme Person who is other than the bound and liberated selves' expressed by the terms, the 'perishable' and the 'imperishable'. He forms a completely different category. All Srutis call Him the Supreme Self. But by that very designation as the Supreme Self, it may be known that the Supreme Person is a category distinct from the bound and the liberated selves. How?  'Entering the threefold world,' supports it. 'Loka' (world) is that which is perceived. There are three such perceivable worlds, He enters the 'three worlds' which can be understood from the authority of the Srutis. These are the world of unconscient matter, the world of conscient selves conjoined with matter, and the world of liberated selves. As understandable from the Srutis, He enters into these three categories as their Atman and supports them. Thus, He is an entity different from the triad which He pervades and maintains. Further He is different, as He is imperishable and as He is the Lord. Being imperishable, He is different from the bound non-conscient matter whose nature is subject to decay. He is different from the bound conscient selves as the latter is subject to Prakrti and follows its laws. He is also distinguished from the liberated selves, because in their previous condition they were connected with matter and mixed with it. Similarly, He is the Lord of these 'three worlds,' a category distinct from those which have to be ruled.