How deep are the roots of Indian civilization?

Almost every aspect of Indian culture is deeply rooted in the past, which is at least 5,000 years old. He then gives an integrated picture of the civilization of those days - variously called the Harappan, Indus or Indus-Sarasvati Civilization. Thereafter he deals with the ethnicity of the authors of this great civilization. With solid arguments, he refutes the theories that there was an 'Aryan Invasion' of India, which destroyed the Harappan Civilization or that there was an immigration of the (BMAC) people from Central Asia.