What in /S/a@nkara's opinion the Upanishads teach, is shortly as
follows.--Whatever is, is in reality one; there truly exists only one
universal being called Brahman or Paramâtman, the highest Self. This
being is of an absolutely homogeneous nature; it is pure 'Being,' or,
which comes to the same, pure intelligence or thought (/k/aitanya,
j/ñ/âna). Intelligence or thought is not to be predicated of Brahman as
its attribute, but constitutes its substance, Brahman is not a thinking
being, but thought itself. It is absolutely destitute of qualities;
whatever qualities or attributes are conceivable, can only be denied of
it.--But, if nothing exists but one absolutely simple being, whence the
appearance of the world by which we see ourselves surrounded, and, in
which we ourselves exist as individual beings?--Brahman, the answer
runs, is associated with a certain power called Mâyâ or avidyâ to which
the appearance of this entire world is due. This power cannot be called
'being' (sat), for 'being' is only Brahman; nor can it be called
'non-being' (asat) in the strict sense, for it at any rate produces the
appearance of this world. It is in fact a principle of illusion; the
undefinable cause owing to which there seems to exist a material world
comprehending distinct individual existences. Being associated with this
principle of illusion, Brahman is enabled to project the appearance of
the world, in the same way as a magician is enabled by his
incomprehensible magical power to produce illusory appearances of
animate and inanimate beings. Mâyâ thus constitutes the upâdâna, the
material cause of the world; or--if we wish to call attention to the
circumstance that Mâyâ belongs to Brahman as a /s/akti--we may say that
the material cause of the world is Brahman in so far as it is associated
with Mâyâ. In this latter quality Brahman is more properly called
Î/s/vara, the Lord.