 Put simply, propaganda is the dissemination of ideas intended to convince people to think and act in a particular way and for a particular purpose. It's crucial to understand that it's the instigator's purpose that defines or distinguishes propaganda from other similar forms of activity such as advertising and education. While the definitions have changed, the concept of propaganda has not really changed. But what has changed are the means of communications from the early print media, both written and visual, to the electronic – I'm thinking obviously film, radio, television and of course now the internet – and this change in the means of communications has had a profound effect on both the speed with which propaganda has been disseminated and also the scale on which it has been disseminated. The term propaganda is a 20th century term pretty much and it essentially came out of the First World War. The first major state propaganda agency was Britain's Ministry of Information, a nice Orwellian term. The idea of information was to, as they put it, direct the thought of most of the world. I think propaganda has become devalued as a word and as a concept because it has been defined so negatively in so many different countries. So for example, if you talk about propaganda, I think to my generation, they would think immediately of the Soviet Union and of the Communist bloc. If you talk about propaganda to an earlier generation, they're probably thinking much more about Second World War and even the First World War but I think that what's happened is that the whole sort of concept of propaganda, spin and all the rest of it has just become defined very, very negatively. We often think of propaganda in terms of its very vivid, infamous iconography such as Nazi propaganda and Stalinist propaganda but really the most powerful propaganda of the 20th century and the 21st century is insidious. Something that we often don't recognize, something that's disguised and it comes from two words, public relations. Words are invented by Edward Bernays back at the beginning of the 20th century when he said that the Germans during the First World War had given propaganda a bad name. He wanted to make it respectable and PR, public relations, has not only made propaganda respectable and I'm talking about PR used by great power such as states. It has made it both insidious and all powerful. I think it is true that even today people still associate propaganda with lies and falsehood as something to be avoided at all costs, almost a sort of cancer on the body politic. I think this misunderstands the basic nature of the concept. Propaganda is about persuading people but it's also about reinforcing existing opinions and prejudices. Aldous Huxley wrote in the 1940s that a propagandist is a man who canalizes an already existing stream. In a land where there is no water he digs in vain and I think this preoccupation with lies and falsehoods misses the basic concept of propaganda that it is ethically neutral, it can be good or bad. The crucial factor I think here is to recognize that the real problem is the monopoly of propaganda. So for example in dictatorships or totalitarian states where you do have a monopoly of the means of communication then of course you have a real problem with propaganda because you are not getting alternative sources of information. How do you measure the success of propaganda? This is a perennial problem, it's a very difficult question to answer. It's often cited that British propaganda in the First World War is a classic example of successful propaganda. Indeed both Lenin and Hitler in the interwar period wrote that they believe that British propaganda during the First World War had a profound effect on the outcome of that conflict. Today the news is happening every single second of every single minute in every single country in the world and it's happening not just via television screens and radio and newspapers and magazines, it's happening on people's phones, on people's iPads, in people's cars, on trains, on planes, all around us all the time the news is unfolding.