(Clockwise from top left) Lord Stern asks about the Chinese restaurant in Calcutta where Sen had hosted a lunch for him; Sen delivers the last lecture of the LSE’s “Space for Thought” series; students queue up to get the book signed by the economist; the audience at the theatre where all 450 seats were occupied before Sen arrived. Pictures by Amit Roy

London, July 28: There are book launches and book launches in London but last night The Telegraph witnessed something a little special at the London School of Economics when Amartya Sen released his latest philosophical work, The Idea of Justice.

Every seat in the 450-capacity ultra-modern Sheikh Zayed Theatre in the LSE’s New Academic Building in Lincoln’s Inn Fields — the UAE had given £2.5 million to commemorate its late ruler — had been taken. There was a discernible “buzz” in the air as students waited for what almost felt like a pop star-cum-guru-cum-academic-cum-stand up comedian (Sen did have several witty one-liners).

Sen was introduced by Lord (Nick) Stern, author of the world-famous Stern report on climate change but who is also the IG Patel Professor of Economics and Government at the LSE.

He has known Sen for 40 years and recalled the luncheon the Indian had hosted for him at a Chinese restaurant in Calcutta on Christmas Day, 1974. (Stern, who was then associated with the Indian Statistical Institute and conducting research in Palampur in Uttar Pradesh, wasn’t quite sure whether it was Peiping on Park Street.)

This morning, Sen told The Telegraph: “I fear I can’t remember the name of the restaurant now. It was not in the Chinatown, but somewhere very central, like on Free School Street or Park Street, but can’t remember much about the restaurant now — the food was good though!”

He said: “I am doing more interviews today, and tomorrow, and then going to Bristol for the evening — another launch event arranged by Penguin — and then I fly to India for the launch there in Delhi and Calcutta.”

Last night turned out to be a memorable evening for those students lucky enough to be present — and judging by the question and answer session they came from all over the world.

Sen was making the final contribution in the LSE’s “Space for Thought” lecture series to which tickets are free but they have to be applied for online.

This is how the lecture by the Novel Prize winner was billed by the LSE: “Amartya Sen explores the ways in which, and the degree to which, justice is a matter of reason, and of different kinds of reason. It is in the nature of reason, says Sen, that it does not allow all questions to be settled from first principles; not everything is in principle resolvable; and different people regard different positions as just.

“But these pluralities are not a disadvantage. Why this is so, and how we may think about justice in a world where one tradition is no longer dominant. Sen’s work is grounded not in idealised justice, but what can be made to work practically, in the real world. He argues that a philosophy of justice should require the agreement not just of the community which is making the laws, but of important outsiders also.”

When the line opened at 10am on July 20, “there were 800 requests within five minutes”, the LSE’s pro-director for external relations and professor of law Sarah Worthington disclosed in her warm-up act last night.

Penguin, which has published the title through its Allen Lane imprint, has said “this major philosophical work, by one of the world’s leading public intellectuals, constructs a new theory of justice, not from abstract ideals or notions of what perfect institutions and rules might be, but from what the results of a system are practically, in the world”.

“It is the most ambitious and wide-ranging book Amartya Sen has yet written,” the publisher added.

Penguin has priced the book at £25 and naturally hopes to sell as many copies as possible.

Sen could have pointed out: “You will be able to pick up a pirated edition for a couple of hundred rupees from a Calcutta pavement hawker.”

Since this was not an option last night, students snapped up all 80 copies that the Waterstone-Economist Bookshop on campus had in stock. Sen sat in the foyer patiently signing each in turn.

“It was full price and sold out within 15 minutes,” said a source at Penguin.

For cash-strapped students to spend £25 is quite a concession for there was no discount offered as is customary on such occasions.

Those who could not get The Idea of Justice bought The Argumentative Indian and joined the long queue for everyone wanted his or her copy inscribed.

Stern, who clearly deserves another good Chinese meal from Sen, told the students: “This is not only a splendid book — thoughtful, scholarly, well written, important in ideas — I think it is going to be a very important book in many ways, including the politics of the new few years. It will be an important book in the political philosophy of the coming decades. So do buy it. On the day of the launch it will be very valuable.”

Sen, who had spoken through the evening about the ancient Indian concepts of niti (policy) and nyaya (justice), brought the house down by observing: “Penguin will never forgive me for it but the most effective way of reading a book is to borrow it from a library.”