Someone tapes a banana to a gallery wall and everyone wants to know the same thing: “How is that art?” It sounds like such a simple and reasonable question. But it’s the wrong one. Artists decide whether something is art. The rest of us only get to decide whether it’s any good.

After the sale of Maurizio Cattelan’s “Comedian” during the Art Basel Miami fair last week, people asked, “Why is that art?” — obviously because they want the answer to be “It’s not.” So let’s go down that road, just for the sake of it:

No! Of course it’s not art. Anyone who thinks a banana taped to a wall — or a urinal placed in a gallery or a set of written instructions or a shark preserved in formaldehyde — anyone who thinks that any of this could be art has to be crazy. Or a con artist. They’re perpetrating a giant fraud. It’s “The Emperor’s New Clothes” all over again. All we have to do is break the spell and agree — all in unison now — that it’s not, it’s obviously not art, and all this craziness will end.

There. Do we all feel better?

Maybe we do. But — I’m sorry to spoil it — I smell bad faith.

If you don’t like something that’s presented as art, if you think it’s offensive or stupid, go ahead and say it’s offensive and stupid. I’m an art critic, I will be right there with you. But to say simply that it’s not art is, for me, a cop-out.

I understand people’s resistance to the idea that art is anything an artist wants it to be — especially when it comes to contemporary art, which can seem ruled by a principle of “anything goes” and is populated by a whole class of mincing neophytes cravenly chasing publicity. But I’m convinced that is the right principle.

Creativity often confounds us. It cracks open the assumptions and expectations to which our minds unthinkingly cling. People used to say that rap music wasn’t music because it lacked melody. Hilarious. When Steve Martin performed stand-up devoid of recognizable jokes, many wondered how it could be called comedy. But people laughed, people danced. Rap went from strength to strength, and no one, as far as I know, boycotted Martin’s shows on the grounds that his routines didn’t meet some established definition of stand-up.

The same occurred, more recently, with comedian Hannah Gadsby, who, before our eyes, disassembled the standard mechanism of comedy — setup and punchline — and dared to find it wanting. There were moments, during her performances of “Nanette” when we stopped laughing and even started to cry. How is that comedy?

Um . . . does it matter?

In contemporary art, once-clear categories get smashed all the time. This can get tedious, of course. But it’s also what makes visual art so dynamic and fun and, in many ways, so far ahead of the rest of the culture.

If a visual artist wants to make art that is beautiful and reassuring, great — I want some of that! If someone else wants to make art that’s ugly and terrifying, I’m all for that, too; it may resonate with my own mortal apprehensions or prompt new insights.

And if someone else — let’s say an Italian provocateur named Maurizio Cattelan — wants to use art to offer up a sharp critique of how art is commodified and if he wants to use humor, theatricality and a sense of the absurd to do so, why should I suddenly say it’s not art? I like laughing at folly, and I, too, think that a whole lot about the art world is completely and utterly nuts.

I may not ultimately think Cattelan’s banana and tape is great art. I might find his gesture facile or obvious or not as smart and challenging as other things he has done. But it’s easy enough to see what he’s doing and why he sees it as art.

What Cattelan has done with “Comedian” — if we want to try taking it seriously for a second — isn’t unrelated to what Gadsby has been doing in comedy. Just as Gadsby made the mechanisms of conventional stand-up almost painfully transparent — revealing them as manipulative, predictable and finally inadequate — Cattelan has turned the act, the truly absurd event, of rich people buying bananas and the ensuing media spectacle into a kind of performance art. Or yes (ha!), a new kind of stand-up.

It’s not the banana, in other words, that constitutes the art. It’s the grotesqueness of the sale and ensuing spectacle, and more specifically, it’s the idea that the system is absurd. The work, in other words, is in sympathy with your feelings about it!

Whether you think it succeeds, “Comedian” is an attempt to make transparent a patently crazy situation — a situation that implicates not only the art market and the wealthy but also the media and our unquenchable thirst for spectacle and sensation. It would be nice if we could end all the craziness by defining it away — by saying, “That’s not art!” But we can’t.

The freedom that contemporary art claims for itself — its sense of being unbeholden to rules or convention — is one of the things I love about it. I see that freedom inspiring people in other fields of endeavor all the time. The most creative people in popular music — Frank Ocean, Beyoncé, Jay-Z, Lady Gaga — get many of their best ideas from contemporary art. It’s the same in architecture, theater, dance and so on.

If you feel differently about such art, that’s okay, and I will agree if you say it has produced mudslides of cynicism and intellectual vapidity. But that’s not the issue here. The issue is whether it’s okay to let artists decide whether what they are doing is art.

Experience suggests to me that it’s the wisest course. We all get the urge to call bull on things we don’t like. We can say, “My child could do that,” or “I could do that,” or even “I did that yesterday!” But to say, “That’s not art” is a different order of response. It’s a lazy and fearful attempt to define something out of existence.

I’m not going to short circuit my right to think for myself — nor am I going to presume to short circuit anyone else’s — by futilely announcing to the world that something is not art. Doing that would solve precisely nothing.