an excerpt from the Katha Upanishad:
Beyond the senses are the objects, beyond the objects is the
mind, beyond the mind is the intellect, beyond the intellect is
the great Atman.
Beyond the great Atman is the Unmanifested; beyond the
Unmanifested is the Purusha (the Cosmic Soul); beyond the Purusha
there is nothing. That is the end, that is the final goal.
In these two verses the Teacher shows the process of discrimination, by which
one attains knowledge of the subtle Self. Beginning with the sense-organs, he
leads up to the less and less gross, until he reaches that which is subtlest
of all, the true Self of man. The senses are dependent on sense-objects,
because without these the senses would have no utility. Superior to
sense-objects is the mind, because unless these objects affect the mind, they
cannot influence the senses. Over the mind the determinative faculty
exercises power; this determinative faculty is governed by the individual
Self; beyond this Self is the undifferentiated creative energy known as
Avyaktam; and above this is the Purusha or Supreme Self. Than this there is
nothing higher. That is the goal, the Highest Abode of Peace and Bliss.
This Atman (Self), hidden in all beings, does not shine forth;
but It is seen by subtle seers through keen and subtle
If It dwells in all living beings, why do we not see It? Because the ordinary
man's vision is too dull and distracted. It is visible to those alone whose
intellect has been purified by constant thought on the Supreme, and whose
sight therefore has become refined and sharpened. This keenness of vision
comes only when all our forces have been made one-pointed through steadfast
practice of concentration and meditation.