Tradition of Debate in India

[Alok Kumar]

The tradition of Shastrath (debate) is considered to be quite old in India.
I wonder if the list members can suggest me a book/article on the history of
this tradition, especially in the ancient period.  Was it O.K. to question
any doctrine or concept in the ancient period?  I would  like know with
specific examples and references.
Alok Kumar
Department of Physics
State University of New York
Oswego, NY 13126.