She writes words on walls. We read them. That’s it. This has been Barbara Kruger’s laconic way of working for more than 40 years, and it has brought her international fame. Her art is terse, assertive, argumentative, pithy and always directed straight at your face.

Of course there are variations. Her phrases used to appear over photographs. The deathless “I shop therefore I am” is printed on a red-and-white calling card held by a black-and-white hand. “Your body is a battleground” runs across a woman’s face, advertising a 1980s pro-choice rally. “When I hear the word culture I take out my checkbook” is emblazoned on a grinning ventriloquist’s dummy, a work that fulfilled its own tart irony by changing hands in 2011 for almost a million dollars.

Kruger used to work entirely in black, white and red, and in her signature Futura Bold Oblique typeface; but that has changed a little. And her phrases have emerged from the gallery, over the years, to appear on buildings, buses, T-shirts, posters and magnets, and on billboards above hurtling motorways. At the Venice Biennale, when she won a lifetime achievement award in 2005, her words ran right up the facade of the Italian pavilion. “Admit Nothing. Blame Everyone”.

In which respect nothing at all has changed. For her first major show in a British gallery in years, Kruger has assembled slews of exhortations, instructions, propositions, rejoinders and exclamations that appear with matching abruptness on the museum walls. They have the status of overheard speech, of shouts from the crowd or disembodied rhetoric, of urgings, rebukes, demands and counter-demands, and they work against each other all the time.

At best they may inspire thought, analysis, debate; at their worst they are hectoring banalities on the lowest level of phatic speech. “Hello Goodbye” runs one classically irritating play-off.

The enormous space of the main upstairs gallery is covered floor to lintel in capital letters 10 and even 20 feet high, in black, white and bright green that blaze and glare, leaving fierce after-images on the retina. “Be Here Now”; “Remember Me”; “Who Will Write The History of Tears?”; “The Brutal, Relentless, Fearful End of It All”. (What does that mean, if it means anything at all? How can an end be relentless?)

The floor is covered with waves of words over which one must walk to make out the next, and the next. They accumulate into one long list — lovers, singers, speakers, posers, thinkers, feelers (Kruger likes a little rhythm and rhyme) stretching away into the distance. Intellectuals, acolytes, sycophants and professors: can she be talking directly to Oxford?

Are these words random sneers (and if so, whose?); are they categories or labels? Do they have agency? Timothy Williamson, Wykeham professor of logic at the University of Oxford, has contributed a catalogue essay on the subject words as labels, the nature of belief, the value of uncertainty, binary oppositions and very fascinating it is too; rather more than the experience in the gallery.

The busy floor palls. The walls bear questions to which there is only one right answer, one senses. “Is There Life Without Pain?” Well, perhaps you believe there is, perhaps that is your joyous experience. It’s always hard to read the tone of Kruger’s work that is its essential and uppermost characteristic, in fact but one can’t help thinking she’d find that answer callow or complacent.

For there is no doubt that she means to keep you on the alert, not relaxing into peaceful contemplation (is what all there is?) “You Are Not Yourself” (Go on then, who am I, and isn’t this pretty basic ontology?) A flashing screen in the next gallery alternates names and images of consumer goods including art, incidentally — before declaring (three times over) — Plenty Should Be Enough!”

Kruger is capable of eloquent concision. One of the works in this show is simply a sentence that builds to a portrait. “Thanks to yoga, yoghurt, life coaches, art, ashrams, philanthropy, real estate, pets, shopping and rehab, you’ve found peace.” It is a miniature life.

It is not, on the other hand, Dorothy Parker. Kruger is rarely as mordant as one might hope, given her lifelong survey of social culture, and nor is she quite the artist as anthropologist.

The observation is all there, to be sure; a wall of emoticons opposite a wall of words gets to the nub of it. Why bother to examine what you feel, still less trouble to find the right words, when you can just use a dumb old smiley? Language loses the battle; the world shrinks even further.

Kruger presents a globe deafened by perpetual communication, in which everyone is online all the time, nobody is listening to anyone else, texting and tweeting are contracting not just language but thought. She was on to this long in advance. The problem, in a sense, is that her own work partakes of exactly this ruthless and simplifying brevity.

“I’m right and you’re wrong”. “Talk is cheap”. It’s like having two kids in nonstop spat in the back of the car. And on the rare occasions when the disembodied voice or voices suddenly appear to be that of the artist herself — “Stop Texting” shouts the screen, alternating with dire photographs of car crashes — one almost misses the to and fro for the sense of receiving a public health warning.

An immense four-screen installation fills the final gallery with hectoring conflict; one talking head per screen in a roundelay of scripted arguments and full-scale rows. You can’t keep up with it, you can’t see all four people at once, you can’t follow the subtitles streaming below like a news channel. A carousel of casual nastiness, cynicism and aggression, it’s daytime talk shows crossed with reality TV, running ad infinitum.

But it is poorly cast and performed so that one is left only with the idea of what might have been. And that’s the problem with this show. It’s not just that every proposition, no matter how diverse, irresistibly induces the same response — that everything is infinitely more complex than this; it’s that the famous method gets in the way. You cannot ignore slogans 15 feet high but you can resist the empty clamour. The art forces itself upon you, every time — that’s its graphic affront — but it doesn’t always hold your mind.

–Guardian News and Media 2014

The exhibition is on until 31 August at Modern Art Oxford