The term Adhikāritva is one of the technical terms seen in the Śāstras. This indicates about the eligibility or the competency for the study of particular Śāstraic discipline. This type of eligibility for the studies of Vedas is scheduled as per the traditional norms; for example, Upanayana is essential for the studies of Veda. Vedic studies is a basic qualification for the studies of Pūrva- mīmāmsa. This may be different for the studies of other branches of learning. Automatically this is different in the case of Advaita Vedanta than that of Pūrva mīmāmsa. Now, this study will be restricted to the basic qualifications prescribed for the studies of Advaita Vedanta. 

We see that studies on material subjects also require certain prescribed qualifications.  It is definite that the academic qualifications, which are proper, should be attained for getting admitted to the higher studies of a modern subject. A student, who desires to become a lawyer, must get admission in a Law College. For the same, he should be eligible with basic qualifications. This eligibility is different for the admission to a medical college. These concern material subjects. Therefore, definitely some other minimum qualifications might have to be prescribed for spiritual subjects also. The philosophical subjects are dealt with on the mental plane. Therefore, they may demand certain mental qualities. Those who have earned these basic mental characteristics, are entitled to study philosophical subjects. Therefore, along with the yearning for the study, they must develop mental characteristics to suit such a philosophy. This higher level of mental attaintment is named as Adhikāritva.

The   Adhikāritva of Advaita Vedanta is constant; it will not change in accordance with the modern changes of life. It is seen that the Advaita  philosophy has had its prevalence from time immemorial. Its ancient masters and the details of their ideology may vary, but their aim and ultimate goal were the same – Supreme Almighty and Bliss. The means and nature of competent aspirants are almost the same in old Advaita, as well as in the modern. Still we shall divide the time span of philosophy into three. Sankara stands as the central landmark. Sankara has contributed an elaborated definition for Adhikāritva. Therefore, it is proper to divide the period of Advaita philosophy into three: 1. Pre-Sankara Advaita philosophy; 2. Sankara philosophy and 3. Post-Sankara Advaita philosophy. 

The first one starts back from Sankara to time immemorial. At the same time, the second one is purely the ideology of Sankara, which is available from his commentaries, treatises, stotras, etc. Actually, the third period is fully related to Sankara because it contains varied Advaita philosophical schools and the philosophy of his disciples. Most of the ācāryas of his later period are his followers or either they followed Sankara with some independent thinking.

The early period before Sankara, i.e. the pre – Sankara Advaita philosophy is vast and also vague. We are not able to collect reference data of such Ācāryas, because their original works are not available to us. But references of their names and some ideologies are available from the quotations of later writers. Vedavyāsa, through his Brahmasutras, mentions some names of early Advaita Ācāryas. He has mentioned the names like Āśmarathya ¹, Auḍulomi ², Kaśakṛtsna ³, Karṣṇājani ⁴, Jaimini ⁵, etc. Some other earlier philosophers are either quoted to oppose their ideology or just quoted to support by later writers.  These names include Bhatṛmitra, Bhatṛprapañca, Upavarṣa, Brahmadatta  and others. We are fortunate enough to get the original works of Bhatṛhari, Gauḍapāda and Maṇḍana Miśra.  Ācārya Gauḍapāda was the paramaguru (teacher’s teacher) of  Śankara. Bhatṛhari was elder to Gauḍapāda and one of his works Vākyapadītya is one to establish the Sphoṭa Brahman. Maṇḍana Miśra was an elder contemporary of  Śankara.  His famous work related to Advaita is Brahmasiddhi. The work of Gauḍapāda is Gauḍapādakārika, in which there was no discussion on  Adhikāritva. Bhatṛhari has also not mentioned anything in his works on Adhikāritva. 

Maṇḍana Miśra in his Brahmasiddhi has discussed the eligibility of a seeker. He has raised six views, which are variant opinions of earlier ācāryas and presented his own siddhanta in this context. Six schools of poorva pakṣa are presented. They are⁶: After enjoying and fulfilling all the desires, a person will be able and eligible for the knowledge of Brahman. After remitting the three debts, he will be Adhikāri for Ātmajñāna based on the Smṛti – \[ain ÇI{ypak«Ty mnae mae]e invezyt!,  (mnu.6.35) Those who perform karma qualifythemselves to enter for the studies of Ātman. This opinion is known as s<yaegp&wKTvNyay>, On observing and purifying through the 48 samskaras, he will be eligible for the knowledge. Some say, on the contrary to this, that these purifying rituals convert him as an Adhikāri for karma only, not for knowledge. This karma method is contrary to the method of Jñāna. Will these two,  together, give one result of either karma or Jñāna.

Maṇḍana objects to each one of these schools and follows the Upaniṣadic method. He says:
“That means one who has restrained his outgoing mental propensities, restrained also his external sense organs, constantly fixed his mind on scriptural passages that explain the nature of Brahman, such an individual is to be advised the knowledge of Atman (by the preceptor) and he is eligible and he only will achieve the liberation. Not others, those who are attracted to the objects naturally, as their instinct. Those who have internalization of the mind towards the self, and stable minded are Adhikaris, because they have adequate competency.”

In the commentary of the above statement, Śankhapāṇi, the commentarian, adds as given below:  
“Here the point is stressed that both Śänta (restrained the mind) and Samähita (self settledness of the mind to Brahman) will get the Realisation. This seen as cited in the Sruti: ‘Therefore, he will visualise Atman in him after having become quiet, subdued, contended,  enduranced and concentrated (Br.Up.4.4.23).⁷ Here, the word Śänta is mentioned as a very essential quality to an aspirant. He should be devoid of all natural instincts connected with desire, hatred, etc. The word Dänta indicates towards the withdrawl of all outside actions. These actions are the results of the previous contacts of the organs with the objects. The results are seen as the extension to attain the desired objects or to averse to undesired. These are the primary essential attribute needed to a spiritual aspirant. Therefore, we can regularise the six qualities into three ie, Śama, Dama and Samadhana, not others.

It is said in short, that those who have attained ‘Śama’, control over mind, ‘dama’ control over sense organs, Uparata, Titikṣa etc. are only eligible and are  competent aspirants for the knowledge of Brahman. They are to be advised by a Guru on the nature of the Supreme Being, following the method of Adhyāropa and Apavāda.  Maṇḍana has followed the traditional method in this matter. Śankara’s disciples and later ācāryās of Advaita philosophy followed the same method. Therefore, post-Sankara philosophers stressed Sankara’s philosophy. Śankara in his commentary for the first sutra, i.e., Awatae äüij}asa, explicitly explained this. Those who have attained the four-fold merits, are competent students to gain the knowledge of Brahman. They are: 1. inTyainTyivvek>  2. #hamuÇawRÉaegivrag>   3. zmdmaidsaxns<pt!   4. mumu]uTvm! c, The first one means the discrimination between things permanent and transient. After getting this general knowledge that Brahman is the only eternal substance and all other than this are transient, then the knowledge of the second one is prescribed. It is the renunciation of enjoyment of the fruits of actions in this world and other worlds. The third one indicates the group of six virtues starting with Śama, Dama, etc. They are: 1. Śama or restraining mental propensities; 2. Dama or restriction over sense organs; 3.Uparati or cessation of external organs and withdrawing from external objects to the matter of Brahman; 4. Titikṣa or the endurance of heat or cold, happiness or sorrow, forbearance; 5. Samādhāna or constant concentration of the mind and to settle slowly in the matters related to Brahman; 6. Śraddha or the faith in the truths of Vedanta. The fourth quality in the four-fold means is mumu]uTvm!  or a desire, inherent yearning for Liberation. 

We shall try to see how these essential qualities are followed and retold by some direct disciples and later philosophers of Advaita ⁹.  Suresvara, direct disciple of Sankara says in his Vārtika: “There is an order that he should be a Dänta first, ie, he should control first the outward spread of mind to the sense organs and from sense organs to the objects outside. Then he should be a Śänta by regularizing the activities of mind. After the same, he should attain the level of Uparata, it is the internalization of the mind towards the self. At this stage, he will enjoy the association of Self always. This order of approach is very important, as like as the proceedings in the line of learning.”

It is true that Śruti has not accomplished any injunction on the matter of attaining Śama, Dama etc. But if the aspirant is pre-equipped with these qualities, then only he will be a Sãdhaka, and then these are the means to proceed to the spiritual field.  Sarvajñātman, the author of Samkṣepaśārīraka states in this way:
The aspirant having his intellect sharpened and cleaned by the destruction of impurity by the performance of various prescribed sacrifices, possessing the four-fold means (as explained in the commentary of Brahmasutra 1.1.1 by Śankara) and desiring to know the Self duly approaches the preceptor who has realized the highest to be known.
The above mentioned strong version of Śankara is based on Śrutis. Śankara has repeated these in his Vivekacūḍāmaṇi also as shown below:
These are the evaluation and advice of sages. Based upon the instructions of the ancient sages, Adi Śankara promises this method of learning as follows:
“In this connection, the sages have spoken of four attributes for attainment. When these are present, devotion to the ultimate Truth will become fulfilled. When they are absent, the approach to it will be failed.
First is a general discriminative capacity between the etrnal and the transient. Next comes the renunciation of the enjoyments of the fruits of actions in this world and also in another world. Then comes a group with six qualities starting with control of mind etc. The last one is the desire to get Liberation.
A general discrimination in the mind that Brahman is real and the world which is seen is unreal. This discrimination in the mind is called the Nityānityavasuviveka.”
In his Vivekacūḍāmaṇi, Śankara has mentioned that  this is the old tradition of sages and they have advised these definitions of Adhikāri. In scriptures, we can see the genesis of these four-fold pre-requisites of knowledge.
An ordinary aspirant reaches to the conclusion by seeing the proclamations of the upaniñad – “as in this world, whatever has been acquired by effort perishes, therefore whatever is acquired in the next world by yägas and other good deeds also will perish, as the result of actions here.” (Ch.Up.8.1.6). The renunciation of the results in this world and another world achieved from the Sutis: “After examining this world of action, “For the sake of Self everything is favour for him” Śanto, dãnta etc (Br.Up.4.4.23) is the genesis for the script starting with Śama, Dãma etc. In the matter  of concentrated contemplation, the genesis can be seen in “Know that Brahman” and approaching a preceptor is indicated through the Śruti – “Varuna went near to his father”.
Śankara has presented the four-fold means in a special order. Commentarians ¹⁰  justify that the first one i.e. inTyainTyvStuivvek> is the cause for the second, i.e. #hamuÇawRivrag>, It means that only after attaining the first one, from the same the second one evolves and gradually from second, it is the cause for the third, while the third acts as the cause for the fourth. In the commentary named Pañcapādikavivaraṇam, it is told and proved that these inTyainTy etc. are formed
by Śankara based on the Śrutis: 
This may be doubted whether these four sādhanas are essential or one or two can be dropped? Otherwise, which is important among the four-fold qualities? Later ācāryas explain that all these qualities are equally important. None of them can be avoided. It is explained in a work named Laghuvāsu-devamananam: 
In a prakarana named Vasudevamananam, insisted the four qualities of Adhikãri as essential. See the reasoning:
“In this world, one can find some with Nityänityavastuviveka, but they may be devoid of renunciation (vairägya). Therefore, non-desired nature for the fruits of actions, either in this world or in another world, should be insisted as essential. From the four-fold attributes, even though the above said qualities are presaent, it is seen in some of the sages, as they are subject to anger, sorrow, desire etc. That is why we should insist on the six virtues, starting with Śama. Even after attaining above three qualities, some of them practice devotion, they practice oneness with Iswara. Therefore the fourth, ie, longing for liberation is also needed.
It is seen in this world that certain practitioners may have discriminative intelligence, i.e. inTyainTyivvek>, but they exist without renunciation. Therefore, #hamuÇawR  etc. is also essential. Even though they might have attained these two, certain saints are seen with heat and anger and short tempered. Therefore, along with this, Śama, Dama etc. are all essentially achieved. Mentally they must be matured. This much is not enough because certain persons may be immersed in saguṇopāsana of lower Gods and will enjoy it fully. Therefore, a desire for Liberation must also be constantly developed.   
The four-fold sādhanas work together, as a unit, and for such a seeker, with the blessings and advice of a teacher who has realized Brahman, can reach the highest level of Realisation of Brahman. It is also named Mokṣa. 
At this stage we shall think over  the competency of an aspirant in general. In different fields of action, success from the efforts in the form of attaining the goal depends mainly on the qualification of the seeker. Then suitable time, place and other circumstances are also helpful in supporting him. (See Vivekacudamani, 1.14). Therefore, in this spiritual field, he would understand generally the Ātman, he shoulod know that what is the intention of the word ‘permanent’, and he should have a discriminaqtive intelligence. Therefore the first level of qualification is given, that from worldly experience he should differemtaite which is real and which stands unreal. Then comes the second quality, then only Vairãgya can be developed, he should occupy the renunciation of the enjoyment upon the fruits of his actions. For achieving such a detachment, he should acquire certain virtues like Śama, Dama, etc. Therefore, they are enjoined, without which he cannot proceed, stopping the desire, anger, etc. But in this stage, a strong yearning for liberation is also neede. It is not important that a seeker wherever he may be, or in whichever Āsrama it may be, but when he achieves the pre-qualifications, he should approach a preceptor, who is a Realised soul. The authority of this type of basic qualification was prevalent from ancient times and is approved by ancient sages. Śankara uses “instructed by sages” (kiwtain mnIi;iÉ> – iv.cU .18). In the list of previous Ācãryas, Veda Vyãsa is also included. That is told by him in Brahmasūtra 3.4.27, that the qualities like Śama, Dama, etc. are auxiliary for an individual in his practices. Anyway, we can say that these qualities of an Adhikäré are essential factors in life, and energising back support to all human beings.