What is self?

"What is the Self? Can you describe it even though it is
so intimate to you, so contiguous to your whole being?
Close your eyes. Shut out the view of your own body.
Immediately, even though you are still not aware of Self,
you will admit that it has no determinate qualities. You
feel it. You know that you are you, but you cannot
describe the Self. The Self does not exist in space. There
are no dimensions to Self. You cannot say that it is so
high, so long, or so wide. Furthermore, the Self has no
time value, because it is always of the Now.
Wherever you are, realizing that you are, there is Self. It is
always of the present. There is no past, nor future to Self.
At times, the Self seems to be absorbed into the
Absolute; you even lose your identity at times, no longer
considering yourself as "John Jones" or "Mary Brown" but
rather that you have a realization of just being-a being
without any limitation, a being that seems to be
everywhere and be everything. Self, then, seems to be in
harmony with all existence. That, too, is a level of
consciousness. To it have been attributed many mystical
names." Ralph M. Lewis