Which of the following does not belong? Diet Coke, Toyota cars, Schubert’s lieder. Not sure? Add in collectible figurines and motocross. And which of these? Lattes, heavy metal, organic food. Not sure? Add in BBC Radio 4 and yoga.

Now imagine a comprehensive inventory of every area of life where aesthetic considerations come into play: it would include books, movies, pictures, buildings and landscapes, interior furnishing, clothing and personal grooming, romance and friendship, manners, and the food we eat out or the food we cook at home. Anyone who reads the news can quickly, almost unthinkingly, sort much of the inventory according to aesthetic sensibilities clustered by political outlook, religion, and socioeconomic status.

Such aesthetic pigeonholing involves value judgements on both sides. Motocross fans are liable to scorn lattes and lieder music. Not long ago, fans of lattes and lieder music would have called motocross “plebian”. Nobody says that any more, but my friends blithely denounce Thomas Kinkade paintings as “bad art”, with the implicit snicker is that this “bad art” has a large audience. Yet Kinkade doesn’t botch what Jackson Pollock did well. He is as different from Pollock as Viennese opera is from Balinese gamelan. Badmouthing Kinkade as bad art is a sneaky way of belittling a genre of painting with a devoted demographic.

Philosophers call this aesthetic tribalism. It’s bad for us aesthetically. It’s bad for us generally. And we can do something about it.

Tribalism is not a case of relationships indicating similar interests. Stamp collectors are not a tribe just because they get together for the mutual benefit that comes with trading, sharing information, and learning new skills. Tribes are something different: they impose conformity on otherwise diverse ecologies. Stamp collectors only form a tribe when they expect each other to wear pocket protectors and read manga, though neither of these particular choices is essential to stamp collecting.

Aesthetic life is a pluralist realm. The forces of tribalism exploit this wonderful feature. Any footwear aesthetic goes with any musical commitment. Having decided on Doc Martins, you are perfectly free to sign up for bansuri lessons. The irony is that it’s precisely because your existing aesthetic commitments play perfectly well with any new ones that you can delegate future decisions to the tribe, without betraying your existing aesthetic self. If you go for Doc Martins and have no preferences about music, it’s easy to prefer the music that gets approval from the Doc Martin tribe.

But we tend to think about aesthetic life in a way that systematically distorts its pluralism. We dutifully recite the dogma of “to each his own”, and “there’s no disputing matters of taste”. You sign up for bansuri lessons and I practice the bag pipe – and pluralism says both are good. Taken literally, the dogmas of taste say nothing more. However, under the influence of tribalism, they acquire a special meaning. They say that we are opaque to each other, aesthetically speaking. Someone who owns a wardrobe full of hemp dresses can hardly imagine switching to lycra. In other words, the dogmas of taste make us forget the pluralism of aesthetic life.

The power of tribalism constrains our aesthetic freedom and also has disturbing consequences for public discourse. As we have seen, wearing Doc Martins is compatible with playing a bansuri, and this suggests that our various aesthetic commitments come with no strings attached. Indeed, it is tribalism that attaches the strings, insofar as it shackles the imagination and makes us regard compatibilities as incompatible. By insisting that Schubert is as incompatible with motocross as blue is with red, aesthetic tribalism collapses the myriad choices through which we could otherwise explore ourselves aesthetically.

When it comes to public discourse, we usually start by seeking common ground—common interests or commitments and common acceptance of the facts—when deliberating together about the problems we jointly face. Yet tribalism undercuts the search for common ground from which we can reason and reach compromise, and the aesthetic dimension of tribalism threatens productive public discourse in two ways.

First, as long as moral and political differences are seen as matters of taste, it is easy to shy away from political disputes. Putting it plainly, social media “likes” make political and moral outlooks, and our responsiveness to facts, a matter of taste. We can see how this has played out in the climate change debate, where facts about climate change have been regarded as a matter of subjective preference. And if we cannot agree upon the facts, it is difficult to have a meaningful public debate.

Second, it becomes more difficult to have fruitful exchanges when we share little common ground. Communal life involves up-close engagement with people who are not exactly like us. The art of living together entails finding solutions that make room for incompatible viewpoints. Aesthetic life should be a shining example of how we can embrace difference. Aesthetic tribalism robs us of that.

Recognising the compatibility of our diverse aesthetic sensibilities can be part of what frees us from the tribalism of our closeted mentalities. The way to rekindle the pluralism of aesthetic life is to balance thinking for yourself and thinking in the position of everyone else. Thinking for yourself is the antidote to running with the aesthetic herd. Putting yourself in other’s shoes is the antidote to the dogmas that easily lead to aesthetic tribalism.

Which of the following does not belong? Lycra, the bansuri, manga. And which of these? Motocross, lattes, Doc Martins, Thomas Kinkade. Let’s dream of a day when these questions make no sense.

Dominic McIver Lopes is Professor of Philosophy at the University of British Columbia and a Fellow of the Royal Society of Canada. He is the author of Being for Beauty.

This article is part of the New Statesman’s Agora series.