Adult Learning Theory

Though written around 1513, more than 500 years ago, Italian diplomat Niccolò Machiavelli's The Prince is still very influential. Listeners turn to it for its direct advice on the question of how to attain - and retain - power. Machiavelli's answer, in brief: use any means necessary to make sure the state survives. Given the changeable nature of politics, the strong ruler that Machiavelli describes may need to lie or cheat, deceive and, if necessary, resort to acts of violence - all the while maintaining an "image" of goodness.

One of the most influential books on economics ever written, Thomas Robert Malthus's An Essay on the Principle of Population remains one of the most controversial too. This 1798 work inspired naturalists Charles Darwin and Alfred Russel Wallace to develop the theory of natural selection. But it has also sparked criticism - Karl Marx famously called Malthus a "lackey of the bourgeoisie." Yet this hasn't stopped leading present-day environmentalists from taking up Malthus's ideas.

British-born American political activist Thomas Paine wrote Rights of Man in 1791 in response to Reflections on the Revolution in France, Edmund Burke's attack on the French Revolution. Burke was wary of tearing down old institutions of government. But Paine argued that revolution is acceptable - in fact, necessary - when government ignores the rights of its people. Not surprisingly, Rights of Man proved very popular in the newly liberated United States, selling over 100,000 copies.

What really happened when the world's two greatest superpowers went head to head during the Cold War? We Now Know is a major reappraisal of the struggle for political and ideological supremacy between the United States and the Soviet Union from 1945 to the Cuban Missile Crisis of 1962.

US psychologist Abraham Maslow's 1943 essay "A Theory of Human Motivation" established his idea of humanistic psychology as a "third force" in the field. He outlined a new approach to understanding the mind, saying humans are motivated by their need to satisfy a series of hierarchical needs, starting with the most essential first. He thought it important for the advancement of psychology to identify, group, and rank them in terms of priority.

Michael R. Gottfredson and Travis Hirschi's 1990 work, A General Theory of Crime, assessed contemporary work in criminology, while also introducing a new, comprehensive theory of crime. At the time, researchers tended to focus on environmental factors that led to crime, not on the criminals themselves. Additionally, crime researchers came from different disciplines and inclined towards thinking about crime only from their particular perspective. This meant ideas about what caused crime, and how to prevent it, were often in conflict.