In his 1532 treatise on the art of politics, The Prince, Machiavelli explained the rules of gaining power and influence, and his name has since become synonymous with the use of guile, deceit and opportunism in human relations. Even psychologists categorise people according to their tendency to Machiavellianism: hence "high Mach" and "low Mach". And the phrase "you've been Mached" has nothing to do with Saturday night TV: in psychology it means you've been successfully and secretly manipulated.
Machiavelli's masterpiece was written in the form of advice to a hypothetical prince on how to rule his kingdom. In it, Machiavelli sets out the rules for acquiring, maintaining, wielding and hanging on to power. He did not celebrate the ruthless application of power, as many believe, but simply laid out the stark reality of human affairs.
He emphasised the importance of reputation in determining advancement, pointing out that all great leaders often do things that have no practical benefit but which enhance their reputation, such as starting a war. They are respected and admired for their ability to solve problems.
Manipulators never lose sight of their goal of personal advancement; they forge friendships and alliances, but they are never distracted by the personal elements in these relationships as these could be used against them if a friend develops an interest opposed to their own. You should be "friendly" and have lots of "friends", but if you want someone you can trust, then get a dog, as Gordon Gekko the unscrupulous billionaire trader says in the classic Machiavellian film Wall Street.
Machiavelli developed his ideas from the political machinations he saw around him. He observed at first hand a failed multiple assassination attempt in which one celebrated Florentine family aspiring to power tried to wipe out another as they both arrived hand in hand at an Easter mass.
The ringleaders were hanged within seconds of the failed attempt. So Machiavelli concluded: "Do onto others as they would do unto you, only do it first and do it conclusively".
In his book he asks: what are the qualities needed to rise through the ranks and assume power over others? In particular, is it better to be loved or feared? Most of us seem to err on the side of one or the other, but if we really want to get on, we need both in our armoury.
Dr Raj Persaud is Gresham professor for public understanding of psychiatry, and director of the Centre for Public Engagement, King's College London.
His latest book is The Motivated Mind (Bantam Press). Email: email@example.com