Br.up.4.3.20 S.B.---ata idam avidyaayaaH satatvam uktam--------------- -------tataH phalam. Therefore, the nature of nescience is that it represents what is infinite as finite, projects things other than the Self, which are non-existent and makes the Self appear
as limited. From this sense of limitation arises the desire for things that appear to be different from oneself (due to ignorance of the truth that everything is but Brahman).
This desire prompts one to action for its fulfillment. Action produces results, and this
leads to further birth. Thus the cycle-kaama, karma, janma-desire, action, rebirth,
goes on indefinitely, as long as ignorance continues. tasmaat na aatmadharmaH
avidyaa---- Ignorance is not a natural characteristic of the Self, because that which
is natural to a thing can never be eliminated, like the heat and light of the sun. B.S.Adhyaasabhaashya---avidyaavadvishayaaNi eva ------s'aastraaNi ca.

    All the means of valid knowledge, such as perception, and even the scriptures, have validity only as long as a person is ignorant of the Self. (All these function only on the
basis of the superimposition (adhyaasa) of the body, mind and organs on the Self. This superimposition comes to an end when avidyaa is eradicated. After that even the
scriptural injunctions cease to be applicable). This primal ignorance is described as beginningless. But this word is not used here in the same sense as that in which it is
used in respect of Brahman. avidyaa is beginningless only in the sense that it has no
cause. avidyaa is the cause of the entire universe according to Advaita.

    It is not possible to classify this avidyaa either as real or as unreal. What is unreal (asat), like a sky- flower, is never experienced. Since avidyaa is experienced, it is not
unreal. According to Advaita, that alone is real, which never ceases to exist. avidyaa,
being removable by knowledge, is not real. It cannot be both real and unreal because
of contradiction. So avidyaa is described as `anirvachaniiya', different from both real
and unreal. This does not mean that it is absolutely unreal. avidyaa has empirical (vyaavahaarika) reality. The universe, which is an effect of avidyaa, also has the
same level of reality. avidyaa, as well as the universe, are said to be indeterminable (anirvachaniiya) and illusory (mithyaa).

    Locus and content of avidyaa : All are agreed that the content (or object) of nescience
is Brahman. But there is difference of opinion with regard to its locus. MaNDana Mis'ra says in Brahmasiddhi that the jiiva is the locus of nescience. Vaachaspati Mis'ra holds
the same view -see his commentary on Brahma suutra-1.4.3. Aanandagiri----Brahman is the locus-commentary on Brahma suutra-1.4.3. Sures'varaachaarya---Brahman is the locus---Naishkarmyasiddhi Ch.3.1. Sarvajnaatmamuni---Brahman is the locus---Samkshepa s'aariirakam-1.319 Prakaas'aatman----Brahman is the locus------VivaraNa- avidyaa is positive avidyaa is not mere negation, as it is antagonistic to Knowledge.

    In Vedaantasaara of Sadaananda, ignorance is defined thus:-Ignorance is something positive, though intangible, which cannot be described as either being or non-being,
which is made of three guNas (sattva, rajas and tamas), and is antagonistic to
Knowledge. Ch.2.34

    In B.G.5.15, the Lord says that Knowledge is covered by Ignorance. What covers
can only be positive and cannot be negative. In Samkshepas'aariirakam 1.320 and
in VivaraNa it is established that avidyaa is positive. The same conclusion has been
arrived at in Sures'vara's Vaartika on taitt. Up. Bhaashya-2.179. See also Samkshepas'aariirakam Chap.3.111. It must, however, be noted that it is only from
the empirical point of view that it is said that avidyaa, while being other than the real
as well as the unreal, is positive and not mere absence of knowledge. From the
absolute point of view, avidyaa does not exist at all.

    See also under the heading Maayaa', where verses from Panchadas'i have been
quoted. avidyaa has two powers avidyaa or Nescience covers Brahman with its veiling power (aavaraNa s'akti) and projects the universe with its power known as vikshepa s'akti-see Viveka chuuDaamaNi, verses 113 and 115. In Vedaantasaara it is said:-
Just as a small patch of cloud, by obstructing the vision of the observer, conceals, as
it were, the solar disc extending over a very large area, similarly, ignorance, though
limited by nature, yet obstructing the intellect of the observer, conceals, as it were, the Self, which is unlimited and not subject to transmigration. Such a power is the power of concealment. (Para 52). The Self, covered by this concealing power of ignorance,
becomes subject to transmigration characterized by the notion of being a doer and an enjoyer. Just as ignorance regarding a rope, by its inherent power, gives rise to the
illusion of a snake, etc., so also, ignorance, by its own power, creates in the Self covered
by it, such phenomena as aakaas'a, etc. Such a power is called the power of projection.
(Paras 53 and 54). avidyaa and maayaa-whether the same or different S'rii S'ankara
treats avidyaa and maayaa as identical -See B.S.Bhaashya-1.4.3.Sures'vara also
does the same. Samkshepas'aariirakam-3.108-109 expresses the same view.

    In Panchadas'i, VidyaaraNya says that prakr.ti constituted of pure sattva is maayaa
and when constituted of sattva mixed with rajas and tamas is avidyaa. Brahman reflected
in maayaa is iis'vara, who is omniscient and is the controller of maayaa. Brahman
reflected in avidyaa is jiiva. In Patanjali's Yoga suutras avidyaa is described as one
of the five `kles'a-s', or causes of man's suffering. (Suutra 2.3); the other four are
egoism (asmitaa), attachment (raaga), aversion (dvesha) and the desire to cling on
to life (abhinives'a). avidyaa is said to be the cause of the other four (2.4). avidyaa
is defined as looking upon what is non-eternal as eternal, what is impure as pure,
what is painful as pleasant and the non-Self as the Self (2.5). avidyaavr.tti

    In deep sleep there is avidyaa as well as avidyaavr.tti. avidyaa, which is the adjunct
(upaadhi) of the Self in deep sleep, is the causal condition of the mind. While the
mind is dormant in deep sleep (sushupti), it is through avidyaavr.tti that ignorance
and happiness are experienced. On waking up, the mind again comes out of its
causal condition and there arises the memory of what was experienced in sleep. svaruupa-jnaana, which is the very nature of Brahman, is not opposed to primal
ignorance. It is this svaruupa-jnaana which reveals the ignorance. The primal
ignorance which is the cause of bondage is destroyed by the mental mode (akhaNDaakaaravr.tti) generated by the mahaavaakyas. This final vr.tti-jnaana
also disappears immediately thereafter, in the same way as the medicine itself
disappears after removing the disease.