Only Self prevails.

No division in Consciousness is admissible at any time as it is always one and the same. Even the individuality of the Jiva must be known as false, like the delusion of a snake in a rope.

As through the ignorance of the real nature of the rope the very rope appears in an instant as a snake, so also does pure Consciousness appear in the form of the phenomenal universe without undergoing any change.

There exists no other material cause of this phenomenal universe except Brahman. Hence this whole universe is but Brahman and nothing else.

From such declaration (of the Shruti) as “All this is Atman”, it follows that the idea of the pervaded and the pervading is illusory. This supreme truth being realized, where is the room for any distinction between the cause and the effect ?

Certainly the Shruti has directly denied manifoldness in Brahman. The non-dual cause being an established fact, how could the phenomenal universe be different from It ?

Moreover, the Shruti has condemned (the belief in variety) in the words, “The person who”, being deceived by Maya, “sees variety in this (Brahman), goes from death to death”.

Inasmuch as all beings are born of Brahman, the supreme Atman, they must be understood to be verily Brahman.

The Shruti has clearly declared that Brahman alone is the substratum of all varieties of names, forms and actions.

Just as a thing made of gold ever has the nature of gold, so also a being born of Brahman has always the nature of Brahman.

Fear is attributed to the ignorant one who rests after making even the slightest distinction between the Jivatman and the Paramatman.

When duality appears through ignorance, one sees another; but when everything becomes identified with the Atman, one does not perceive another even in the least.

In that state when one realizes all as identified with the Atman, there arises neither delusion nor sorrow, in consequence of the absence of duality.

The Shruti in the form of the Brihadaranyaka has declared that this Atman, which is the Self of all, is verily Brahman.

🕉 Excerpt from: Aparokshanubhuti
By Adi Sankaracharya, 
Translated by Swami Vimuktananda
Verses 43 – 55.