In a talk at the Oxford Union on Saturday, former prime minister Kevin Rudd exhorted future leaders to 'preserve peace', 'preserve our liberty' and 'save capitalism from self-cannibalising itself.'

The Oxford Union, founded in 1823 as Oxford University's debating society, is regularly visited by world political, cultural and academic heavyweights. Speaking before Rudd was 1994 Nobel laureate in economics John Nash, on whom the Oscar-winning film A Beautiful Mind was based. Nash, 85, stuck around for Rudd's talk.

Rudd opened with 'My fellow Australians', a not inaccurate one-liner given the heavy Australian representation among the 300-odd students in attendance.

Rudd, now a senior fellow with the John F Kennedy School of Government at Harvard University, was billed by the union as the first Australian prime minister to publicly support same-sex marriage. Understandably, then, some who weren't in the know were a bit surprised when he started speaking Chinese. On asking for a quick hand-show of nationalities present, Rudd used the Mandarin term for The People's Republic of China, to the giddy gasps of the Chinese students in the hall.

He went on to quote almost verbatim an anecdote he offered up to the Oxford Business Alumni Forum in Sydney in 2011 and has used on other occasions. On his first gig interpreting for Australian Ambassador Ross Garnaut at the Great Hall of the People in Beijing, Rudd recalled, he decided to spice up his boss's formulaic opening platitude. He ended up rendering 'Australia and China currently experience a relationship of unprecedented closeness' as 'Australia and China are currently experiencing a fantastic mutual orgasm.' The line worked as well in Oxford as it did in Sydney.

The substance of Rudd’s speech was on politics and purpose. He outlined five great global challenges for the next generation of world leaders. First was to preserve the peace:

While some may conclude that conflict and war are simply not possible any longer in this post-modern world of ours today, in this post-modern Europe, in this post-modern Asia, I believe that to be wrong.

Rudd's second challenge was the struggle to 'preserve our liberty.' He conveyed the need to remain vigilant against forces that 'diminish our freedom' and waxed on the virtues of the 'ancient Judeo-Christian ethic' with 'the great admixture of the enlightenment.'

Third, Rudd touched on economics, covering familiar territory for those who read his 7900-word essay on capitalism in The Monthly in 2009:

While we are right to conclude across most of the world that capitalism is an overwhelming force for good in the world… the truth is capitalism does not liberate all. It will fall to you, the leaders of the future therefore, to save capitalism from self-cannibalising itself. Not just its creative destruction, not just its tendency towards monopoly, not just its inability to deal with market failure, not just its inability to deal with equality of opportunity, nor its incapacity to deal with the ever-widening inequality itself… it will fall to you to craft an inclusive capitalism, not an exclusive capitalism… otherwise the simple truth is…the political constituency of capitalism will collapse.

Rudd’s comments failed to get a rise out of John Nash, who seemed preoccupied with something on the far side of the hall through this part of the speech.

Rudd’s last two global challenges were again favourite topics for the former PM: China and climate change. On China he said that crafting 'a common future together with our friends in China, rather than seeing the rise of China result in a trend towards conflict and war...is the great question of our age.' On climate, he said the current generation of political leadership had enjoyed 'at best marginal success' and linked the issue back to the rise of China:

Climate Change... now has the capacity to prevent China from realizing its century-long national dream to return to its place of central prominence...though it is not for China alone to solve...it is a global challenge.

After tackling the big issues, Rudd took questions from the crowd. He defended the former Labor government's policies on asylum seekers, climate change and indigenous Australia. One compatriot in the audience tried to goad him into commenting on the current government in language the former PM would understand: 'Do you think that the Abbott government is giving ordinary Australians a fair shake of the sauce bottle?'

Rudd's reply was diplomatic: 'I'll leave that question for my colleagues in Australia to answer.' He added: 'My concerns now are the greater challenges.' Certainly, that was the impression one gained from his talk.

Photo courtesy of @OxfordUnion.