Debt is one of the great subjects of our day, and understanding the way that it not only fuels economic growth, but can also be used as a means of generating profit and exerting control, is central to grasping the way in which our society really works.

David Graeber's contribution to this debate is to apply his anthropologists' training to the understanding of a phenomenon often considered purely from an economic point of view. In this respect, the book can be considered a fine example of the critical thinking skill of problem-solving. Graeber's main aim is to undermine the dominant narrative, which sees debt as the natural – and broadly healthy – outcome of the development of a modern economic system. He marshals evidence that supports alternative possibilities, and suggests that the phenomenon of debt emerged not as a result of the introduction of money, but at precisely the same time.

This in turn allows Graeber to argue against the prevailing notion that economy and state are fundamentally separate entities. Rather, he says, "the two were born together and have always been intertwined" – with debt being a means of enforcing elite and state power. For Graeber, this evaluation of the evidence points to a strong potential solution: there should be more readiness to write off debt, and more public involvement in the debate over debt and its moral implications.

South Korean economist Ha-Joon Chang used his 2003 work Kicking Away The Ladder to challenge the central orthodoxies of development economics, using his creative thinking skills to shine new light on an old topic. Creative thinkers are often distinguished by their willingness to challenge received ideas, and this is a central aspect of Chang's work on development. Before Chang, the received wisdom was that developing countries needed the same kinds of economic policies and institutions as developed countries in order to enjoy the same prosperity. But, as Chang pointed out, the historical evidence showed that First World economic success was, in fact, due to exactly the kinds of state intervention that modern development orthodoxy shuns. Western affluence is the product of precisely the kinds of state control - of protectionism and the setting of price tariffs - that developed countries have since denied the developing world in the name of economic freedom and 'best practice.' By insisting that Third World nations should adopt these economic policies themselves, argued Chang, the West is actually stifling Third World economic prospects - kicking away the ladder. His carefully reasoned argument for a novel point of view was closely based on the critical thinking skill of producing novel explanations for existing evidence, and led many to question development orthodoxies - sparking a rethink of modern development strategies for less-developed countries.

Milton Friedman was arguably the single most influential economist of the 20th-century. His influence, particularly on conservative politics in America and Great Britain, substantially helped – as both supporters and critics agree – to shape the global economy as it is today.

Capitalism and Freedom (1962) is a passionate but carefully reasoned summary of Friedman’s philosophy of political and economic freedom, and it has become perhaps his most directly influential work. Friedman’s argument focuses on the place of economic liberalism in society: in his view, free markets and personal economic freedom are absolutely necessary for true political freedom to exist.

Freedom, for Friedman, is the ultimate good in a society – the marker and aim of true civilisation. And, crucially, he argues, real freedom is rarely aided by government. For Friedman, indeed, “the great advances of civilization, whether in architecture or painting, in science or literature, in industry or agriculture, have never come from centralized government”. Instead, he argues, they have always been produced by “minority views” flourishing in a social climate permitting variety and diversity.” In successive chapters, Friedman develops a well-structured line of reasoning emerging from this stance – leading him to some surprising conclusions that remain persuasive and influential more than 60 years on.

South Korean economist Ha-Joon Chang used his 2003 work Kicking Away The Ladder to challenge the central orthodoxies of development economics, using his creative thinking skills to shine new light on an old topic.

Creative thinkers are often distinguished by their willingness to challenge received ideas, and this is a central aspect of Chang’s work on development. Before Chang, the received wisdom was that developing countries needed the same kinds of economic policies and institutions as developed countries in order to enjoy the same prosperity. But, as Chang pointed out, the historical evidence showed that First World economic success was, in fact, due to exactly the kinds of state intervention that modern development orthodoxy shuns. Western affluence is the product of precisely the kinds of state control – of protectionism and the setting of price tariffs – that developed countries have since denied the developing world in the name of economic freedom and ‘best practice.’

By insisting that Third World nations should adopt these economic policies themselves, argued Chang, the West is actually stifling Third World economic prospects – kicking away the ladder. His carefully reasoned argument for a novel point of view was closely based on the critical thinking skill of producing novel explanations for existing evidence, and led many to question development orthodoxies – sparking a rethink of modern development strategies for less-developed countries.