Rockstar philosopher Michael Sandel can not only make you question the morality of trading in human organs but can also make a case for paying civil servants million-dollar salaries.
The Harvard professor's appearance yesterday was the best attended event of the ongoing Singapore Writers Festival, with 1,245 people packed into the National University of Singapore's University Cultural Centre.
Instead of giving a lecture, Professor Sandel, 62, conducted a 90-minute interactive session.
First, he posed questions and had members of the audience stand and debate the pros and cons of matters from legalising trade in human organs to paying children to get good grades or read books.
Later, he answered questions such as one from moderator Kenneth Paul Tan, associate professor at NUS' Lee Kuan Yew School of Public Policy, about paying those in public service million-dollar salaries.
"I have a lot of sympathy for this way of compensating civil servants," he said.
"It's a way of making corruption less likely. It's also a way of making people, no matter their economic or class background, able to serve in public service. It does honour and recognise public service in a way that's not easy to achieve.
"I can't speak about the situation in Singapore because I don't know enough," he added. "But reflecting my experience, in America, public service is disparaged or not accorded recognition comparable to those who have achieved success in business."
Prof Sandel teaches political philosophy at Harvard and is famous for questioning the effect market forces are allowed to have on societies.
His most recent book and the subject of yesterday's session is What Money Can't Buy: The Moral Limits Of Markets (2012).
Possibly his most famous is Justice: What's The Right Thing To Do? (2009). It has the same title as his course at Harvard, which brings in the ideas of thinkers such as Immanuel Kant and Aristotle to help students debate public issues such as taxation and citizenship.
The course has attracted 15,000 students since 1980 and millions more since a 12-episode televised version of the course was made freely available online in 2009. In China alone, the videos have reached 20 million people.
To many in the audience, he represents a moral compass.
Singaporean Annabelle Fabia-de Arroz, 51, who is the public relations manager for public-speaking group Toastmasters International, said: "These are some questions I've been asking myself too: 'Is it fair that teachers should be paid much less than bankers?' I'm very interested in what he has to say."
"Today, there are very few things that money can't buy," he said.
"The greater the tendency to put a price on everything, the greater the risk that market thinking will erode or crowd out non-market values to do with community, family, civic life. We need to have a public debate about where market values serve the public good and where they do not."
He gave the example of paying children to get good grades or read more. Several members of the audience said this worked in Singapore - one father pays his three-year-old and 18-month-old to read storybooks - and that it can be argued that a good salary and job are the "payment" for working hard in the school system.
Prof Sandel then brought up an American experiment where schoolchildren were paid $2 for each book they read. This had the pupils picking up more books, but also choosing shorter ones to read. This could indicate the failure of the experimental aim, which was to develop a love of reading.
"I question whether all values can be translated without loss into a single uniform value of money," he said.
"I think we reach for market mechanics as if they were neutral ways of resolving public questions that would otherwise be controversial.
"We know we live in a pluralistic society where people have different religious, spiritual traditions and markets seem to be a way to decide public questions without having to engage in messy debates."
• The Straits Times is the official media partner of the Singapore Writers Festival. For more stories on the festival, go to www.straitstimes.com/tags/singapore-writers-festival-2015