The seeker experiences truth in two stages – first, there is the feeling of truth and later, there is the seeing of truth. Sage Patanjali calls the seeing of the truth pragna and its unfolding in seven stages has been explained in the yoga-sutras. He calls the feeling of truth viveka and four sutras in the yoga-sutras explain the various aspects of viveka.
Let us see how in the story of Shantanu and Ganga, in the Mahabharata, Ganga represents the feeling of truth, and Shantanu our logical mind. Even though they marry, Shantanu cannot understand why Ganga drowns his seven children.
The great king Prateep was doing penance on the banks of the Ganga to be graced with the birth of a son. The river, in the form of the maiden Ganga, appeared before him and sat on his right thigh. Seeing her, the King said, "O bearer of good fortune, what can I do to please you?" She answered, "O King, I saw you and have desired you, please do accept me." The king replied that only a daughter sits on the right thigh, the wife sits on the left and so he would only accept her as a daughter in-law, promising that she could marry his son who was yet to be born.
Shantanu was born to King Prateep and was crowned king when he came of age. Before retiring to the forests, Prateep told Shantanu of the promise. Shantanu then spent his time meditating upon the river Ganga. When the beautiful and celestial Ganga appeared before him, he fell in love with her immediately. Ganga agreed to marry Shantanu on the condition that he would neither question anything she did nor utter a negative word to her, to which Shantanu agreed.
Seven children were born to Shantanu but Ganga drowned each of them in the river immediately after their birth. When the eighth child was born, Shantanu stopped Ganga from doing the same. Since he violated his promise, Ganga left Shantanu and took along with her their eighth son. She came back to return Shantanu his son when he was sixteen. She explained to him that the eight children were the great Vasus who were cursed to be born on earth and she had promised to free them from mortal bondage as soon as they were born.