What do we mean by the term "intellectual" , and what is a "public intellectual"? It is an odd fact of English culture that it is largely a term of abuse and, when asked to name one, we almost always turn to the continent, particularly France. A typical intellectual in France, we think, will hold down a job as a professor - preferably of philosophy - have a column in a mass circulation daily newspaper, be involved in politics and appear on the cover of Vogue.
Our aversion to intellectuals, or to the term, may go back to when we were at school where nobody likes a "swot". In fact, almost any kind of braininess is disparaged: scientists are mad-haired "boffins", tech-savvy kids are "nerds", and people can be "too clever by half". Indeed, we would claim that we are naturally practical thinkers and too full of common sense to produce such highbrows - a situation not helped by many of the people who we consider to be intellectuals denying the fact.
One problem is that of definition: what qualifications are required and what sort of activities does someone have to engage in before they can be called an intellectual? One possible definition is that public intellectuals should be independent of those in power and critical of received ideas. Furthermore, he or she must be someone who raises embarrassing questions in public, contests dogma, and who cannot be persuaded to join governments or corporations.
Let's take a thinker from last century whose theories still have an impact today and see if the definition fits: John Maynard Keynes was an economist who worked for the Treasury and wrote influential books on monetary policy, an art collector, and a member of the Bloomsbury group of writers, artists and intellectuals. Perhaps we need to adjust our definition slightly!