We know relatively little about the method of teaching in ancient India, but teaching by example must have played a major role. In a story from the Chandogya (viii, 8-12), Indra and Virochana want to learn about the Self from a famous teacher called Prajapati. When they approach him, he simply tells them to stay with him. After 32 years he finally asks his eager students why they have come. When they tell him what they want to know, he gives them a very short answer and when they don't get it, he shows them how they can find out for themselves. What is more, when they come to a wrong conclusion, he does not even correct them, but peacefully waits to see whether they realise their error by themselves. Only Indra does, and so he is invited to stay with the guru for another 32 years. Indra receives the full truth only after a total of 101 years. All we learn about the method of teaching is the simple injunction “Stay with me”.
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