He explains how Urdu came up as a language and grew as a language. It has now been lost and needs to be revived (Kajtu makes the case for Sanskrit as well).
He says Urdu was basically a khariboli:
Urdu is the language which was created by the superimposition of some features and vocabulary of the Persian language on a Hindustani (Khariboli) foundation. Thus, Urdu is a language created by the combination of two languages, Persian and Hindustani. It is for this reason that at one time it was called `Rekhta’ which means hybrid*.
Khariboli is simple or spoken Hindi, as contrasted to literary Hindi which is used by many writers and public speakers. Khariboli is an urban language. It is the first language of the common man in the cities of what is known as the Hindi speaking belt (Uttar Pradesh, Bihar, Rajasthan, Madhya Pradesh, Delhi, Haryana, Himachal Pradesh, etc.) and is the second language in the cities of many parts of the non-Hindi speaking belt, not only in India but also in Pakistan.
What led to its growth? Well it was the linkage of the khariboli to markets:
Almost all cities in the world originated as market places (mandis). This was only possible when the productive forces had developed to an extent that people were producing more than they could themselves consume, and hence the surplus had to be sold or exchanged. In other words, commodities (i.e. goods for sale or exchange, and not for self consumption) began to be produced. Since the seller and the purchaser had to have a known place where the transaction of sale and purchase could take place, market places (mandis) were created, which later became cities.
Now the seller and purchaser must have a common language, otherwise the transaction of sale would not be possible. Hence Khariboli arose as that common language of the market.
This shows that in vast areas of north India the rural population speaks different dialects, but the urban population had a common language, Khariboli. How did this happen?
This happened because a vast common market had been created in India (due to the development of the productive forces) even before the coming of the Mughals. A trader traveling from Bihar or Madhya Pradesh could easily sell his goods in a city in Uttar Pradesh or Rajasthan or Punjab because there was a common language, Khariboli, which both seller and purchaser knew (apart from knowing their local dialects). Thus Khariboli is the common language of the cities in large parts of India. Even in many parts of the non-Hindi speaking belt Khariboli is understood and spoken as a second language. Thus, if one goes to Kolkata or Bangalore or Gujarat or Lahore or Karachi or even in many parts of south India he can converse in Khariboli with people living in the cities (though there might be difficulty in rural areas).
Interesting take..Role of language in economics/commerce is always an interesting area of discussion. See this fascinating post on role of languages and whether English should become the numero uno language for commerce..
It will be interesting to verify Justice Katju’s claims with some empirical work as well..
Keeping economics aside, the speech is an interesting take on urdu as a langauge..