Śaivism, centred round the worship of Śiva, is a very ancient religious cult of India. Śaivasiddhānta, also known as Tamil Śaivism, is an important contribution to the Śaiva lore of South India. Its basic canonical works were composed by Meykaṇdār, Aruḷnandi (also spelt as Aruṇandi), Jñāna Sambandhar and Umāpati, all of whom lived during the period 13th—14th centuries. These four have been designated as ‘Sanātana Ācāryas’ or ancient teachers.
Aruḷnandi was the family preceptor of the young Meykaṇḍār. The story goes that puffed up with vanity, he once asked his pupil Meykaṇḍār about the nature of ignorance. Meykaṇḍār, the young saint simply looked at the proud questioner himself as if in reply. The teacher immedi-ately realized that he himself had been pointed out as a specimen of ignorance, and, overcome by shame, became a disciple of the young saint, assuming the name Aruḷnandi Śivācāriār.
He has written a commentary called Śivajñānasiddhi on Meykaṇḍār’s basic work Śivajñānabodha which itself is in twelve sūtras or aphorisms. This work is in two parts, the first, ‘Parapakkam,’ refuting other schools of philosophy and the second, ‘Supakkam,’ expounding the fundamentals of his own school. The latter is in verse and is considered to be a commentary on Meykaṇḍār’s work. Another work, Irupāvirupabtu is also attributed to Aruḷnandi.