It's the weekend and you are heading out to meet friends at the cinema. You are looking forward to seeing the new thriller by a favourite director. But then you discover that some of your friends would rather see the latest superhero movie, or some a new romantic comedy. Everybody pauses, uncertain how to proceed. You decide to get everyone to see the thriller. You won't force them – after all, they are your friends and unlikely to remain so if you threaten them. You could bribe them by offering to buy the tickets – but movie-going is expensive enough as it is, and you don't want to set a precedent. So you decide to try and persuade them – to get them to really want to go. But how?

You could begin by telling your friends about reviews you have read recommending your chosen film and trashing the others – or by pointing out the relative box office success of the movies on offer. But what reviewers do your friends trust? Do they want to see a hit movie or are they the sort of people who like to "discover" hidden gems?

Perhaps you should remind them that on previous visits to the cinema your choices have been good ones. And all you want is for everybody to have a good time. Alternatively you might explain just how much you have been looking forward to the movie after a really bad week. Are your friends likely to be moved by pity or should you appeal to other feelings?

Perhaps these appeals – to the authority of reviewers, your own character, and to your friends' emotions – seem too manipulative. You could try logic. Movie-going may not be an exact science but there are degrees of reasonableness. If a director's movies have been dire since that first breakout hit then it's a good bet that the new one will be weak. You might argue that the superhero blockbuster is good but the genre can never be truly great; that one of the movies has a lead actor with a bad track record; that the comedy is so long the bar will shut before it ends.

However strong your convictions about quality cinema may be, these alone will not win the day. You need to make an argument. And a successful argument must appeal not to just anyone in general but to your friends in particular. It must be adapted to their estimations of movie reviewers, feelings and beliefs about you and your character, and rely on rational claims of a kind they will recognise.

What is true of the cinema is – in this case – also true in public and political life. In a democracy, rather than force or bribe people to assent to our ideology, we try to win them over through persuasion. That can be a challenge. It requires us to understand where other people are coming from and to develop arguments that are outward-facing.

Not everyone thinks as we do. People have different experiences and possess different information; they have different values and do not always share our criteria of judgment. To persuade them we have to make connections with our audience – with what they might think, feel and be familiar with. This is not about tricking people or fooling them. It is about truly persuading them to share our views on a particular issue – and that means developing a relationship.

A glance at the newspapers and much of the internet demonstrates, however, that many people think the purpose of public communication is to reflect well on themselves – to announce their own importance, specialness or cleverness. An infamous academic chooses not to be convincing but to increase his brand value by performing provocatively; a troll communicates publicly but seeks only private "lulz"; shouting things your audience already believes, yet pretending that you're not allowed to say them, seems to be an easy route to success on talk radio or the op-ed pages. But the only thing such people are saying with their arguments is "look at me!"

Online communication makes easy the simple affirmation of our beliefs, the monetisation of strident "opinion" and the anonymous onanistic expression of inchoate hostility. And that means more arguments – but less persuasion.

True persuasion is democratic. In giving people reasons to act with us we recognise that they aren't inferiors who can be compelled but thinking, feeling and speaking beings. And true persuasion is an art. Contrary to the books on the self-help and business psychology shelves there are no magic "words that work". You have to cultivate an "eye", developing a feel for situations and empathy for those you want to persuade. The name of that art is "rhetoric".

Of course, you don't need to bother with any of this if you and your friends just go and see your favoured films separately. But that is to give up on society, politics and progress. If people cannot persuade or be persuaded then there can be no shared beliefs, co-ordinated collective action or intellectual evolution. The only change will come from force, bribery or manipulation.

In defiance of such a bleak outcome, Comment is free will over the coming week run a series on how to argue in the spirit of Isocrates, the ancient Greek philosopher and rhetorician: "the kind of art which can implant honesty and justice in depraved natures has never existed and does not exist … But I do hold that people can become better and worthier if they conceive an ambition to speak well, if they become possessed of the desire to be able to persuade their hearers."