Sages, Siddhas (persons who have gained the eight great mystic powers) Sages, Yogi's (Devotees of Yoga) survive by practicing this art (Sulimunaikalai), acquire special power through spiritual knowledge about the past, present and future periods. With sulimunai Nadi as the basis, its seven other sub-divisions (sub-divisions of sulimunai) can be practiced separately at different percentage levels.

The sulimunaikalai and its sub-divisions enable Sages to understand through their spiritual power, the results the good and bad deeds yield (of the past lives) to the souls who come in search of them. Then, with the aid of the man kalai (Sulimunai) and other sub-divisions of the same kalai, which go a long way in making the Sages, attain spiritual knowledge and enable them to offer splendid explanations to the world.

The results are accurately explained to the minutest detail to souls who seek the help of the Sages. The sabtha (Seven) Nadi kalai (sub-divisions of Sulimunaikalai) are Aththi, Alambudai, Gaandhari, Sangini, Singuvai, Purudan and Guru. With the secret images of the sabtha Nadigal as the basis of support, the spiritual knowledge of the good and bad deeds (of the past births) are compared with the minute secrets of the nine planets and finally clear explanations are offered to the world.

Therefore this kind of astrological advice is known as Nadi Astrology ( Nadi Shastra ). The original treatise of Nadi Astrology ( Nadi Jyothishya ) has been composed in the form of poetry. Tamil is a divine language with the presence of life in it. Therefore, there are vowels, (vowels in the Tamil language) called Uyir eluththukkal-letters representing life, Mey eluththukkal-letters representing body and Uyirmey eluththukkal-letters representing life and body.

Apart from these letters there is a letter known as Aayutha eluththu, which makes the other, letters function. Apart from these four classes of letters there is a fifth class, which comprises of masculine and feminine letters. The fifth class is a Divine secret class known only to the celestials (Deva's).