These are the intellectual section of the Hindu writings, while the first four are intuitional. And the fifth inspirational and emotional. Darsanas are schools of philosophy based on the Vedas. The Agamas are theological. The Darsana literature is philosophical. The Darsanas are meant for the erudite scholars who are endowed with acute acumen, good understanding, power of reasoning and subtle intellect. The Itihaas, Puranas and Agamas are meant for the masses. The Darsanas appeal to the intellect, while the Itihaas, Puranas, etc., appeal to the heart.
Philosophy has six divisions (Shad-darsana). The six Darsanas or ways of seeing things,are usually called the six systems or six different schools of thought. The six schools of philosophy are the six instruments of true teaching or the six demonstrations of Truth. Each school has developed, systematized and correlated the various parts of the Veda in its own way. Each system has its Sutrakara, i.e., the one great Rishi who systematized the doctrines of the school and put them in short aphorisms or Sutras
The Sutras are terse and laconic. The Rishis have condensed their thoughts in the aphorisms. It is very difficult to understand them without the help of commentaries by great sages or Rishis. Hence, there arose many commentators or Bhashyakaras. There are glosses, notes and, later, commentaries on the original commentaries.
The Shad-Darsana (the six schools of philosophy) or the Shat-Sastras are:
The Nyaya founded by Gautama Rishi
The Vaiseshika by Kanada Rishi
The Sankhya by Kapila Muni
The Yoga by Patanjali Maharshi
The Purva Mimasa by Jaimini
The Uttara Mimasa or Vedanta by Badarayana or Vyasa
The Darsanas are grouped into three pairs of aphoristic compositions which explain the philosophy of the Vedas in a rationalistic method of approach. They are:
A Sutra or an aphorism is a short formula with the least possible number of letters, without any ambiguity or doubtful assertion, containing the very essence, embracing all meaning, without any stop or obstruction and absolutely faultless in nature.
The Sutrakara or the composer of the aphorisms is said to be as happy as one would be while getting the first male child, if he is but able to reduce one letter in his abstruse Sutra of far-fetched words and ideas. The best example of the greatest, the tersest and the most perfect of Sutra literature is the series of aphorisms called the Ashtadhyayi composed by Panini. Panini is the father of all Sutrakaras from whom all others seem to have borrowed the method of composition. The Sutras are meant to explain a big volume of knowledge in short assertions suitable to be kept in memory at all times. The six Vedangas and the six systems of Hindu philosophy form the twelve sets of Sutra literature of the world. In addition to these, there are later compositions like the Narad-Bhakti Sutras, the Sandilya-Bhakti Sutras, etc., which also wish to assume an equal form with the famous Sutras mentioned above.
A Bhashya is an elaborate exposition, a commentary on the Sutras, with word by word meaning of the aphoristic precepts, their running translation, together with the individual views of the commentator or the Bhashyakara. The best and the exemplary Bhashya in Sanskrit literature is the one written by Patanjali on the Vyakarana (grammar) Sutras of Panini. This Bhashya is so very famous and important that it is called the Mahabhashya and its celebrated author is specially called the Bhashyakara. Patanjali is the father of Bhashyakaras. The next important Bhashya is the one on the Mimasa Sutras written by Sabara-Swami who learnt the art from Patanjali’s commentary. The third important Bhashya was written by Sankara on the Brahma Sutras, in close following with the Sabara-Bhashya. The Bhashyas on the six sets of aphorisms dealing with Indian philosophy were written by Vatsyayana, Prasastapada, Vijnanabhikshu, Vyasa, Sabara and Sankara. On the Vedanta or Brahma Sutras, there are about sixteen Bhashyas, like those of Ramanuja, Madhava, Vallabha, Nimbarka, etc.
A Vritti is a short gloss explaining the aphorisms in a more elaborate way, but not as extensively as a Bhashya. An example is Bodhayana’s Vritti on the Brahma Sutras.
A Varttika is a work where a critical study is made of that which is said and left unsaid or imperfectly said in a Bhashya, and the ways of making it perfect by supplying the omissions therein, are given. Examples are the Varttikas of Katyayana on Panini’s Sutras, of Suresvara on Sankara’s Upanishad-Bhashyas, and of Kumarila Bhatta on the Sabara-Bhashya on the Karma-Mimasa.
A Vyakhyana is a running explanation in an easier language of what is said in the original, with little elucidations here and there. A Vyakhyana, particularly of a Kavya (poetry and prose), deals with eight different modes of dissection of the Sloka, like Pada-Chheda, Vigraha, Sandhi, Alankara, Anuvada, etc. This forms an important aspect in the study of Sanskrit Sahitya Sastra (science of Sanskrit literature). An Anu-Vyakhyana- like the one written by Sri Madhava- is a repetition of what is already written, but in greater detail. An Anuvada is merely a running translation or statement of an abstruse text of the original. Tika is only another name for Vyakhyana. The best Vyakhyanas are of Vachaspati Mishra on the Darsanas, especially on Sankara’s Brahmasutra-Bhashya.
Tippani is just like a Vritti, but is less orthodox than the Vritti. It is an explanation of difficult words or phrases occurring in the original. Examples are Kaiyata’s gloss on the Mahabhashya of Patanjali, Nagojibhatta’s gloss on Kaiyata’s gloss, or Appayya’s gloss on Amalananda’s gloss on the Bhamati of Vachaspati Mishra.
The Tevaram and the Tiruvachakam which are the hymns of the Saiva saints of South India, the Divya-Prabandham of the Alvar saints of South India, the songs of Sant Kabir, the Abhangas of Sant Tukaram and the Ramayana of Sant Tulasidaas- all of which are the outpourings of great realised souls- are wonderful scriptures. They contain the essence of the Vedas.