I am an idiot. You could be one too and it would not be disappointing. In fact, I recommend it. Idiocy is misunderstood. It has come to suggest a deficient intellect, a synonym for stupidity, what the Oxford English Dictionary defines as a slowness of mental processes.

Originally, an idiot was simply someone outside conventions. The word is related to idiosyncrasy, an attractive property indicating a life-enhancing individualism rather than shambling, dull-eyed slowness.

Authentic idiots are individuals set aside from beige groupthink because they have colourful opinions of their own. I love opinions. We idiots do. Having opinions is what separates us from cavemen. So I detest it when people sneeringly say: "That's just your opinion," as if to suggest that opinions have very little value because they are the sovereign possession of an individual. On the contrary, opinions are hard-won and therefore extremely valuable. A person who says: "That's just your opinion," is unlikely to be an idiot, but is probably rather stupid.

Opinions are informed patterns of thought; they give knowledge its texture and style. Opinions start conversations. To have opinions, an active imagination is required. And imagination, as Victor Hugo almost said, is intelligence with a backbone.

In the same way, an opinion is knowledge sent on interesting vectors. I love it that my friend, Mark Borkowski, the PR idiot-savant, says: "There is nothing so dismal as a fact." Borkowski is a man with opinions. In the discipline of Information Theory, facts have as low a status as Borkowski suggests.

One of the key works in this new discipline was a 1948 paper by mathematician Claude Shannon. According to Shannon, facts are mere data — crude, passionless measurements. "I am 5ft 10in," is a fact and is very boring. But to say "I am 5ft 10in and, because I am so stunted, feel terribly cheated in life's race," is information and therefore, much, much more interesting.

Opinions are actually quite rare, since unusual qualities such as knowledge and speculative intelligence, not to mention a taste for dissent, are required to generate them. If you do not have any, is it possible to acquire some to make yourself socially attractive and economically useful? To begin opinionising, you need first to acquire knowledge.

Gustave Flaubert made this his subject more than a century ago. In his unfinished novel Bouvard et Pecuchet, he writes about two clerks who, on winning an inheritance, decide to acquire all the world's knowledge.

Predictably, they became confused and eventually paralysed by their own ignorance. His anti-heroes were almost autobiographies: "My deplorable mania for analysis is doing me in," Flaubert told his confidante George Sand. Flaubert resolved his deplorable mania for analysis by becoming interested in opinions. As an appendix to Bouvard et Pecuchet, Flaubert published the curious Dictionnaire des Idees Recues, usually translated as a "Dictionary of Platitudes", a satire on the lazy conversational conformism of provincial France. So what is an opinion?

The thesaurus offers: belief, conviction, idea, persuasion, view, feelings, inclination, sentiment, bias, speculation, supposition, estimation and judgment.

The dictionary is more snooty, saying that opinions are "judgments resting on grounds insufficient for complete demonstration". These are grounds where we idiots feel most comfortable: we have plenty of mere facts, but feel confident that we can improve on them. Original opinions are as rare now as they were in Flaubert's Rouen.

A character in a novel contemporary with Flaubert says: "I never offered an opinion until I was 60 and then it was one which had been in our family for a century." It's a dismal fact that opinions flourish in periods without a dominant religion. Neither a fine Victorian gentleman nor a medieval monk need them. Existence of a culture with many individuals possessing fascinating and combative opinions might be a defining test of civilisation. But that's just my opinion.

The great thing about opinions is that their quality is judged not by their predictability but by their exceptionality. They are contrarian, not conformist. The Duke of Wellington disapproved of his soldiers cheering because it was very nearly an expression of a personal opinion, thus dangerously close to mutiny. Old opinions become collective property, as they did in the salons of Normandy satirised by Flaubert, but new ones come from bold individuals. That's their essential property.

The mathematician G.H. Hardy, himself both a genius and an idiot, said: "It is never worth a first-class man's time to express a majority opinion. By definition, there are plenty of others to do that."

We are often told, I think quite correctly, that the survival of our economy depends on a culture which stimulates creativity. Existence of opinions is one test for a healthy creative culture. So down with economists and their dismal facts and banal metrics. We need more idiots with strong views. Ludwig Wittgenstein believed that if people never did silly things, nothing intelligent would ever happen. We really do need more idiots.

The Telegraph Group Limited, London 2012

Stephen Bayley is the author of A Dictionary of Idiocy.