Atma is not available as an isolated entity

The sakshi chaitanyam , that is atma, is not available as an isolated entity. What is isolated, is essentially time bound and space bound, which means it has a location in terms of space and in terms of time a beginning and an end. 

But we see , that which is consciousness atma is the knower, and never the known, hence is never time or space bound.

If one were to think of chaitanyam or atma, with regards to the jagad, one has to rely on shruti alone, which says that this atma is the kAranam or cause, and it pervades the jagad, since jagad is nothing but effect.

Thus, there is no other way to think of atma, as anything BUT the whole, all that is here is one whole, and that atma can be none other than the whole. Knower, known , knowledge all 3 is the whole, one brahman, that is atma.