In the previous lessons, there was mention of Bhavana Traya. We had also learnt about Samshaya Bhavana. When there are various types of sentences in the Upanishads, how to understand the real purport? –this doubt had come up. It was mentioned that to understand the different types of sentences found in the Upanishads, we have to use "Shadvidha Lingas". Let us now understand about the Shadvidha Lingas.

1. Upakrama & Upasamhara
The method in which the discussion of a topic begins is called "Upakrama" and the method of concluding is called "Upasamhara". There should be coherence between the beginning and the conclusion of a treatise. Then we can conclude that the topic that is discussed at the beginning and the end is the Tatparya of the treatise.

Most of the ancient Indian scriptures have paid appropriate attention to Upakrama and Upasamhara so that the reader can understand the Tatparya of the treatise. Consider the example of Ramayana written by sage Valmiki. It begins with the narration of the noble qualities of Lord Rama and concludes with the narration of the coronation of Sri Rama. By this, the reader can understand that by if one emulates the good qualities of Sri Rama, one can achieve victory and, on the other hand, if one develops the bad qualities of Ravana, one will be annihilated.

Chandogya Upanishad is one of the major Upanishads. The great sentence – "Tattvamasi" (thou art that) is found in the sixth chapter of this Upanishad. This sentence is like a crowning jewel of Vedanta Shastra.

This great sentence has made the Upanishad one of the most important Upanishads. The opening verse of this Upanishad is – "Sadeva somyedamagra aseet – Ekamevaadviteeyam". It means "before this world (came into being), there was only "Sat". It is only one. It is without a second". After this sentence, many other Vedantic aspects have been dealt with in this Upanishad. The concluding sentence is, "Eikadaatmyamidam sarvam – tat satyam – sa atmaa – tattvamasi shwetaketo". The meaning of this sentence is, "the manifest universe is infact the primordial Sat itself. That Sat is Real. That itself is Atma. O!Shwetaketu, You are that Sat"

Thus, we can see that the Upanishad begins with the explanation of Sat and concludes with the same Sat. The theme of the Upanishad is also "Sat". We can therefore understand that to stress the fact "You are that Sat" is the purport (Tatparya) of this Upanishad. This method of narration is called Upakrama-Upasamhara.

2. Abhyaasa
Repeatedly saying something that has been said earlier is called as "Abhyaasa". The father cautions his son by repeatedly telling him to be careful. When his son undertakes travel to some place, the father showers his son with precautionary words. "Take care of your wallet! Do not believe strangers! Beware of pick-pocketers. Keep your purse in a safe pocket!" – cautions the father. By repeatedly warning his son, the father wants to convey to his son that if the money is safeguarded, he can safely return home, come what may. We can understand that safeguarding the money is the Tatparya of the words of caution showered by the father on his son. If the purport is understood on account of repeatedly saying something, such repetition is called "Abhyasa".

The statement –"Tattvamasi" appears in nine contexts in the Chandogya Upanishad. "Tat" means that primordial matter which alone existed before the world manifested; "tvam=you"; "asi = are". "You are that" is the meaning of that sentence. When Shwetaketu heard this from his father for the first time, he was not convinced and expressed his doubt. His father clarified his doubt and again said "Tattvamasi". Each time he cleared a doubt, He said "Tattvamasi" (nine times in all). Because the sentence "Tattvamasi" has been repeated so many times (every time a doubt was cleared), we can understand that the Tatparya of the Upanishad lies in demonstrating the oneness of Jeevatma and Paramatma. This is called "Abhyasa Linga".