The Vedas form the fundamental basis of our religion. They are the words of Brahman and are said to be Brahman itself. These were littered by great ṛṣis (Seers). They are the oldest literary specimens of the world. Their language is an ancient form of Sanskrit. The Vedas are four in number called the Ṛgveda, Yajurwda, Sāmaveda and Atharvaveda. Each Veda comprises two parts, called the Karmabhāga and the Tattvabhāga--the portion that treats of action (karma) and the portion that treats of reality (tattva). The conduct to be followed by those who aspire to acquire puṇya or virtue is detailed in the former portion and the eternal truths of life are described in the latter portion. Brahman is that by knowing which everything is known and so the portion of the Veda which treats of Brahman is the most important portion. It is called the Vedānta or the Upaniṣad. The former portion may again be divided into two parts called the Mantra part and the Brāhmaṇa part. The Brāhmaṇa portion refers to the details of the ritual and indicates the particular mantra to be recited in each ritual act; the Mantra portion supplies the mantras. The two parts are mixed up in the Kṛṣṇa yajurveda; in all the other Vedas they are found separate.

Although the Ṛṣis first uttered Vedas, we should not think that they composed them. The Vedas, according to Hinduism are eternal. They have been existing for all time and are beyond time. It is said that even the world is created by Brahman in accordance with the Vedas. The Vedas are transmitted to the men in different ages either by God himself or through sages inspired by Him. So the sages, by the grace of God, visualised the Vedas and transmitted them to us. As they are not composed by men, the Vedas are infallible. The minds of men are fallible and so whatever a man does is liable to error. But the Vedas are not so. There can be no mistake in them and they compel recognition and response. They are eternal, spiritual imperatives which require to be spiritually obeyed. In accordance with the above view, the language of the Vedas is called the Devabhāṣā or Divine language. The linguistic evidence is in favour of the high antiquity of the Vedas and its eternal holiness. The age of the Vedas cannot be historically determined as they are beyond history and are super-historical, not merely pre-historical.

Though the last portion of every Veda is the Upaniṣad or Vedānta, still Upaniṣads are not all attached to the Vedas. A large number of the Upaniṣads arose on the model of the Vedānta. The Aitareya, the Kauṣītaki, the Kaṭha, the Taittiriya, the Iśa, and the Chāndogya are the last portions or Vedānta of the respective Vedas. Besides these there are some more Upaniṣads which are as important and authoritative as the above. They are the Bṛhadāraṇyaka, the Śvetāśvatara, the Muṇda and the Maṇdūkya, the Maitrāyaṇiya and the Kena Upaniṣads. Of these the Bṛhadāraṇyaka belongs to the Śukla yujurveda, the Śvetāśvatara and the Maitrāyaṇiya belong to the Kṛṣṇa-Yajurveda, the Kena to the Sāmaveda and the Muṇda and the Maṇdūkya to the Atharvaveda. Excluding the Śvetāśvatara and the Maitrāyaṇiya, the remaining Upaniṣads are generally termed as the Ten Upaniṣads. They are the authorities for our Vedānta system and are frequently quoted by our Ācāryas in support of their views. Besides these, there are nearly a hundred other Upaniṣads which underlie our sectarian practices and symbols.

It should not be supposed that every Upaniṣads gives a succinct account of any one system of philosophy. They are rather discussions on different topics comprised in the systems. The whole body of Upaṇisadic literature has been studied, and the contents have been systematised and expounded by Bādarāyana or Vyāsa in his Uttaramimāṁsā Sūtra or Darśana. The Sūtras and the Upaniṣadic statements or śrutis on which they are based are differently interpreted by different Ācāryas according to the system of philosophy advocated by them. In this way different systems of Vedānta arose, like Advaita, Viśiṣtādvaita, Dvaita, Śaiva etc. Most of the Ācāryas wrote commentataries on the important Upaniṣads in accordance with their systems of philosophy.

The next authority for our religion is the Dharma Śāstras. They are of two categories, the Sūtras and the Smṛtis. The Sūtras, as their name indicates, are in the form of aphorisms and the Smṛtis are in metrical form. If śruti is what is directly revealed to the Ṛṣis, the Smṛti is what is recollected by them and recorded afterwards. The Dharmaśāstras give the code of conduct applicable to each section of society and to the whole society in common. All that is contained in the Dharmaśāstras is said to be taken from the Vedas which teach fundamental ethical truths and they claim to teach nothing new. If there is any explicit contradiction between what is laid down in the Vedas and what is taught in the Dharmaśāstras, the former are to be followed in preference to thelatter, as they are absolutely and universally true. If there is anything new in the Dharmaśāstras and there is nothing corresponding to it in the available Vedas, we have to suppose that the corresponding portion of the Veda is now extinct but was available to the authors of the Dharmaśāstras. We should not discard what is laid down in the Dharmaśāstras on account of this accident. But when the Dharmaśāstras of two Ṛṣis prescribe different courses of conduct with regard to the same subject, we should not reject either or both as wrong, but it should be understood that we are at liberty to follow either course at our option. But if there is tradition in our family with regard to one of the courses, we should follow that alone as such a tradition perpetuates an ancient Dharma practised by the rest.

The Dharmaśāstras are the concluding portions of the Kalpasūtras. The Kalpa is one of the six Aṅgas of the Vedas. They are Śikṣā or phonetics, Vyākaraṇa or Grammar, Chandas or prosody, Nirukta or derivation and Kalpa or procedure. The whole Kalpa teaches us all the procedure for the Vedic rites, domestic rites and duties to humanity in general. But all Dharmasūtras that we inherit are not the concluding portions of Kalpasūtras. Some Ṛṣis have written complete Kalpasūtras while others wrote only particular portions. To the former class belong the Dharmasūtras of Āpastamba, Hiraṇyakeśin, Bodhāyana and Vaikhānasa. The Dharmasūtras of Gautama and Vasiṣṭha are independent works and no Kalpasūtras by the same authors are available.

The traditonal number of Smṛtis or law books is eighteen. They are (1) Manusmṛti, (2)Parāsarasmṛti, (3) Vasiṣṭhasmṛti, (4)Śaṅkhasmṛti, (5) Likhitasmṛti, (6) Atrismṛti, (7) Viṣṇusmṛti, (8) Hāritasmṛti, (9) Yamasmṛti, (10)Aṅgirassmṛti, (11) Uśanassmṛti, (12) Samvartasmṛti, (13) Bṛhaspatlsmṛti, (14) Kātyāyanasmṛti,(15) Dakṣasmṛti, (16) Vyāsasmṛti, (17) Yājnavalkyasmṛti and (18) Sātātapasmṛti. All these Smṛtis are equally authoritative but the Manusmṛti has commanded universal respect from the authors of all other Smṛtis and authors of the Itihāsas and Purāṇas because it is the most comprehensive and the most elucidative or clear. The Parāsarasmṛti, is considered to be the standard work for this Kali age. It enumerates exhaustively the special rules for the Kali age. It is said in the Manusmṛti itself that Manu's laws apply to the Kṛtayuga, Gautama's laws to the Tretāyuga, the laws of Śaṅkha and Likhita to the Dvāparayuga and those of Parāśara to the Kaliyuga.

There are some other works which are written by the Ṛṣis like the Dharmaśāstras and which are considered as equally authoritative although they do not strictly come under the category of Dharmaśāstra. These are Itihāsas, Purāṇas, Āgamas and Tantras. The Itihāsas describe how the duties taught in our Smṛtis are discharged by different individuals, how men should act when there is apparent conflict of duties, and thereby create in the minds of people a desire to follow dharma and to shun adharma. The Purāṇas describe how the incarnations like those of Rama and Kṛṣṇa come down to the level of man in order to elevate men to the divine level and reveal to us the mightly power of God by describing the course of creation and destruction and the right and wrong manner of governing the people. The Āgamas contain rules for the construction of temples and shaping of arcas and the consecration and worship of the latter. The method of pleasing the Gods in an easy manner and thereby attaining advantages in this and the next world of svarga and finally mokṣa by following the Yoga is described in the Tantras.

The Itihāsas are the Rāmāyana and the Mahābhārata. The Rāmāyana teaches how the conduct of the people towards different persons is to be regulated by upholding ideals for each case through the story of Rāma and Sitā. The Rāmāyana is as much a story of Rāma as of Sitā and teaches stridharma also. The way in which a son should obey his father, the manner in which the brothers should love each other, the way in which the wife should obey her husband, the manner of the devotion of a servant towards his master, how friends should love each other and work for mutual good; how men and women should conduct themselves towards each other, the feminine virtues of gentleness and love and several other principles of our religion are taught through the life and adventures of Rāma and Sitā. It also brings home to all people the principle that people should be honoured for their moral worth and not for their birth and that pious creatures too deserve respect and service. Above all the Rāmāyana is termed a śaraṇāgatiśāstra and teaches the cardinal principle of our religion that a man who sincerely seeks another for protection should never be abandoned. God as redeemer is anxious to save mankind even if they at least once pray for His mercy. The book also illustrates the principle that God incarnates Himself here in times of historic crises in different forms when the world is filled with vice, for the purpose of saving the virtuous and punishing the wicked. Punishment is only an act of kindness to redeem the wicked from their career of vice and every effort is made to reform them. This last principle is better illustrated by the other great Itihāsa the Mahābhārata. Several other principles of our religion are taught in this work through its episodes such as truthfulness, godliness, purity of women, mercy towards supplicants, forbearance, penance and so on. So many principles of our religion are illustrated in this work that it is termed a Dharmasāstra itself and is even called the fifth Veda. Whole chapters in it are devoted mainly to teach dharma incidentally in the course of the story for the time being. The Mokṣadharma, the Viduranīti, the Sanatsujātlya, and the Anugita are some such important sections. But the most important of these which has acquired universal reputation is the Bhagavadgita (the Lord's song or teaching) in eighteen chapters of about 700 stanzas. Although a chapter in the epic, it has acquired independent recognition by virtue of the highest teaching enshrined in it. At the commencement of the Great Battle, Arjuna feels doubt as to the course of conduct he should follow and seizing the occasion, a sermon on conduct has been taught to him and through him to the world. Karmayoga, Jñānayoga and Bhaktiyoga are taught in all their detail in the first, second and third sextants of the work. The fundamental principles of our religion which are of universal appeal have been clearly taught in this work. The general principles that none should shrink from doing his duty in whatever difficult position he is placed, that everyone who sincerely worships God, in whatever form it may be, will certainly be saved, that the mercy of God alone can save humanity from their sins and the like taught in it have made it the universal text-book of all religions and secured for it world-wide recognition. Our people have recognised it as one of three basic authorities of our religion and philosophy by including it in the Prasthānā-traya. There are innumerable commentaries on it and translations of it. Everyone should read it and put the principles taught in it in practice.

The Purāṇas describe the history of the world. They describe how the world is created, how it is preserved and governed and finally how it is periodically destroyed. The world of cit-acit is eternal; it is subtle in pralaya and gross in sṛṣti. They show how the morality of the world is preserved by God, how the wicked are punished and then redeemed and the virtuous saved. They describe the different methods and incarnations of God at critical periods in the world to maintain its moral and spiritual order. They teach the principles of our religion through their episodes. They also proclaim the glory or vibhūti of the arcāvatāra of God through their descriptions of the power of the different kṣetras and they also describe the holy tirthas in our country. They describe the methods of penance and devotion to God to attain salvation. They therefore form one of the important class of text-books for our religion. The most important of them are eighteen in number. They are divided into three classes called Sātvika, Rājasa and Tāmasa according as they extol the glory of Viṣṇu, Brahma or Śiva.

There are an equal number of Upapurāṇaswhich mostly deal with the glories of different Gods.

The Āgamas are treatises by sages on the practical side of religion. They contain rules for the construction of the temples, making of arca, consecration of the temples and idols, worship of the arca and expiatory ceremonies for acts of commission and omission. Incidentally they treat of town planning to show the place of temple in a planned town and the qualifications of the worshipper. The various incarnations of God are also represented in arca and different kinds of arca are consecrated for different purposes of worship. These Āgamas are two-fold, the Vaiṣṇava and the Śaiva according as they treat of the temples, arca and worship of the different forms of Viṣṇu or Śiva. The Pancarātra and the Vaikhānasa are the Vaiṣṇava āgamas. The former is said to be taught by Nārāyaṇa Himself, while the latter is taught by Saint Vikhānas. The ancient work on the Āgamas are called the Saṁhitas. They are Pādmasaṁhita,

Paramasaṁhita,Sattvatasaṁhita,Kapinjalasaṁhita, Iśvarasaṁhita,Parāsarasaṁhita, haradvajasaṁhita, Ahir- budhnyasaṁhita and Viṣṇutilaka.The Vaikhānasa Saṁhitas are said to be four composed by the four Ṛṣis; Atri, Marīcī, Kāśyapa and Bhṛgu. All the works by these authors have not survived to us. Śaiva āgamas are said to be twenty-eight in number.

Each Āgama has four sections in it called (1) Caryā (2) Kriyā (3) Yoga and (4) Jñāna. The first treats of the daily duties; the second of the worship of God; the third of the practices tending to the control of the senses and for the meditation of God. The last treats of the nature of God, the constitution of the body and mukti.

Tantras are practical treatises of religion. By means of worship of arca or yantras by means of repetition of mantras or mystic utterances, by means of upāsanas, they provide courses for developing the hidden power in man leading to the realization of God. These are also used for the attainment of worldly desires.

All the above literature is in the Sanskrit language. But besides this, there is a large body of religious literature in Tamil which is considered to be equally authoritative in Viśiṣtādvaita and Śaiva siddhanta. They are works of the Vaiṣṇava Ālvārs and Śaiva Nāyanmārs. They are a class of highly gifted saints who, by their wisdom and conduct, have realised God and had communion with Him. Their works are the outpourings of their religious consciousness. The Vaiṣṇava religious hymns consist of four thousand stanzas and are collectively known as the Divyaprabandham. The Ālvārs or Vaiṣṇava saints are twelve in number and their works, as they are collected in the Divyaprabandham., are as follows. The first three Ālvārs, Poygai Ālvār, Bhutat Ālvār and Pey Ālvār have each 100 stanzas to their credit in Iyarpa. Tirumaliśai Ālvār has to his credit 96 stanzas in Iyarpā and Tiruccandaviruttam (120 stanzas) in Mudalayiram. Nammālvār, the greatest of the Ālvārs, has four compositions and the famous Tiruppāvai (30 stanzas) of Āṇdāl are also included in the Mudalāyirarn. The above poems along with the Irāmānujanūttandādi of Tiruvarangattamudanār constitute the 4000 stanzas of the Divyaprabandham. Highest philosophical truths are embodied in these Tamil hymns of the gifted Ālvārs and so these are considered as important for Vaiṣṇava religion as the Upaniṣads; and the two, the Tamil Divyaprabandham and the Sanskrit Upaniṣads are styled Ubhayavedānta. But the most significant point about the literature in the vernacular is that it reveals the greatness of the arcāvatāra or idol-worship. It embodies the spiritual experiencesof the Ālvārs in the different temples. In this manner Śrinivāsa has been extolled by nine of the Ālvārs. The Śaiva religious hymns in Tamil are collectively known as the Tirumurais. They are twelve in number. The Tevāram of Tirujñānasambandar, Tirunāvukkarasu (Appar) and Sundarmurti constitutes the first seven Tirumurais. Tiruvācakam and Tirukkovayār of Mānikyavācakar form the eight. Tiruvicaippā and Tiruppallāṇdu of different authors form the ninth. Tirumular's Tirumantram is the tenth. The eleventh consists of 40 poems by 12 authors. Periyapurānam (otherwise called Tiruttoṇdar purāṇam; of Sekkilar constitutes the 12th. Here too the glory of the arcāvatāra of Śiva is mainly described. The Tamil hymns are designed to inspire feelings of veneration and love towards God besides presenting valuable truths. The devotional songs of Tāyumānavar and Pattinattār addressed to Śiva are as popular amongst the Śaivites as the psalms of the Nayanmārs.

Śaivism is embodied in the philosophic system known as Śaiva Siddhanta and Śaiva Siddhanta is therefore called the philosophy of Śaivism and it is traced to the Upaniṣads like Vaiṣṇava Siddhānta. It is chiefly contained in Śivajñānabodham by Maikaṇdan Śivajñānasiddhiyār.

There is a large body of similar religious hymns in the Sanskrit language also. These constitute the stotra literature. They are small hymns consisting of from one to 100 stanzas in praise of a deity, describing the devotee's absolute surrender to God, admitting his sinful nature and his utter helplessness to attain mukti unless the Deity out of His natural and immense mercy pities his condition and redeems him from his career of sins. They reveal the bhakti or devotion of the devotee and his earnest desire for union with God. The number of these devotional hymns is very large and only a few important and early ones can be mentioned here to serve as examples. The stotras by Śankarācārya are significant as they are composed by a philosopher who held that Brahman was formless and attributeless. The Stotraratna of Yamunācārya comprises 65 stanzas and embodies high philosophical truths. The Gadyatraya of Rāmānuja is an equally important triplex. In the first he seeks the mercy and protection (Śaranāgati) of God. In the second he prays to Śrīranganātha of Śrīrangam. In the third he prays to God to accept himself. The Mukundamāla of Kulaśekhara Ālvār is another famous hymn of forty stanzas. The importance of bhakti or devotion and the mercy of God are clearly brought out in this hymn. Śrīguṇaratnakośa is another important hymn of 61 stanzas. Then there are poems praising several arcāvatāras like, Śrīrangarājastava, Sri Varadarājastava, etc. The Nāmāvalis may also be mentioned here as they help us to meditate upon God by repeating His various names.

The devotional songs of Tyāgarāja in praise of Rāma deserve special mention. The songs of Annamācāryulu on Sri Veṅkateśvara are full of high devotional fervour.