Victor Papanek argued that all men are designers. None perhaps more effective than the early 18th-century pirate Edward Teach, the formidable Blackbeard. Teach's reputation as an indomitable pirate relied on the visual persona he created. Not just the beard itself but the whole ensemble of heavy coat, big boots and huge dramatic hat with lighted matches sputtering beneath the rim struck such terror in his victims that resistance fell away. He had no need of a degree in graphics to realise the longdistance effect on those who saw the Jolly Roger. This kind of basic human instinct for designing is one of the main themes of Alice Rawsthorn's lively and stimulating book.

This is a welcome publication for many reasons. First, deluged as we are with ever more enormous books on architecture, there are very few intelligent books about design. In this area Stephen Bayley was the pioneer, with a constant stream of witty, erudite and challenging writings on design from the 1980s onwards. More recently, in 2008, Deyan Sudjic entered the arena with The Language of Things. Rawsthorn's approach is different, more socially concerned, wider ranging in her interests and, yes, more feminine. It was Rawsthorn, don't forget, who created such a storm during her years as director of the Design Museum by promoting an exhibition on the flower decorator Constance Spry.

Another of her favourites is the Hungarian designer László Moholy-Nagy, a charismatic figure whose students at the Bauhaus named him Holy Mahogany. Moholy took to dressing in a boiler suit, not just as a practical measure but as a symbolic garment, marking his commitment to making the rapprochement between industry and art. He invented the Light Space Modulator, a machine for creating the experimental pools of light and shade, an object Moholy considered so essential to his work that he took it with him in his flight from Nazi Germany in the mid-1930s. To get this peculiar contraption through various European customs he described it as hairdressing equipment.

Rawsthorn adopts Moholy's central tenet: "Design is not a profession but an attitude." She argues that design is not, as most people construe it, just a matter of superficial styling. It's not simply the curves on a sleekly covetable sofa or the angle of those glamorous high heels. According to Rawsthorn, design is "concerned with the whole process of analysis, visualisation, planning and execution". It affects all human lives, for better or for worse.

She draws pertinent examples from her own experience. Rawsthorn, author of a very good biography of Yves St Laurent and now design critic of the International Herald Tribune, is a seasoned traveller and she describes the bliss of arriving in the clarity and orderliness of Zurich airport as opposed to the bewildering chaos of Heathrow or JFK. The difference is simply a question of the signage, implemented in Zurich back in the 1970s by the brilliant Swiss graphic designer Ruedi Rüegg. Where at Heathrow the competing signs and symbols induce panic, in Zurich the traveller feels calm and in control.

We all have our own examples of innovations that seem like improvements but turn out to be the opposite. Rawsthorn cites the espresso pod, the neatly sealed capsule that is faster and less messy than ground coffee. But what about the packaging of those tiny capsules? Rawsthorn reminds us sternly that the functional strengths of the espresso pod are negated by its "environmental weaknesses and death of integrity".

An even worse example of designer overload is the bunch of bananas repackaged for sale in a supermarket in what is described as "organic packaging". Repackaging bananas, surely nature's best example of the perfect pre-pack, and then calling the repackaging "organic"? Surely that way designer madness lies.

Rawsthorn keeps a sharp historical perspective, reminding us of how Giorgio Vasari in the 16th century defined Leonardo da Vinci as an early example of a designer after seeing his immaculately detailed drawings for machinery and engines. But her new book is intended less as design history, and more a succinct survey in 13 brisk chapters of where design is now.

The effect of digital technology is proving both liberating and unsettling. The things we see and use are changing with unprecedented speed as attention spans grow shorter, visual awareness heightens and desires for distractions intensify. New products are being invented almost daily while others become obsolete. What happened to the telephone? Who needs an alarm clock when your smartphone will awaken you? For some, these rapid changes seem baffling. Rawsthorn sees the "elemental role" of design in acting as our friendly negotiant of change.

Try the doorbell test. The world is now divided into those who automatically press a doorbell with their index finger and those who use their thumb. Which you do will, Rawsthorn tells us, "reveal your age almost as accurately as the way you dance or how wrinkly your hands are". All right, since you ask, I use my index finger, originating as I do in a pre-digital age, whereas thumb users are people of a younger generation whose practice in typing text messages and playing on games consoles has rendered their thumbs nimbler than any of their fingers  a pertinent example of how the designed environment changes people's everyday behaviour.

In this quickly shifting world the designers' responsibilities become more complex. Far gone are those days of certainty I knew back in the 1960s when I was design critic for the Guardian. The subject matter of design was then what were rather primly called "consumer goods". The thinking of that time was the simplistically optimistic hope that good design would improve the lives of the deserving British public. Design was an aesthetic offshoot of the welfare state.

Functionally pure tableware and cutlery, refrigerators, textiles and clean-lined convertible sofabeds were selected year by year to receive the coveted Design Centre Awards. The prize-winning designers were the nation's design heroes. I married one of them [David Mellor] so I should know.

The scene described by Rawsthorn is altogether different. Since then designers have endured Margaret Thatcher's "creative industries" policy followed by Tony Blair's Cool Britannia years. No wonder they have turned into such driven, anxious creatures. Never mention Raymond Loewy's all too capitalist mantra "good design is good business", still less his sweeping statement that a designer's main responsibility is "to keep his client in the black". These days such beliefs seem as outdated and embarrassing as jokes about bra-burning feminists.

Rawsthorn's most subtle and interesting chapters concern the rise of the designers' conscience, their involvement in a multitude of projects that improve the lives of "the other 90%" of the world's population. These are the people who have in the past benefited least from the design profession's skills.

She mentions the way the speeding up of our lives has set up a contrasting craving for nostalgia and quirkiness, vintage fashion, folklore and pretend games. Here she could have made more of the considerable revival in handmaking of special oneoff objects at the highest level of imagination, for example the resurgence of the beautiful book. I also feel that she underestimates the hidden dangers in increasing design sophistication, especially in the area of military weaponry. Barnes Wallis's dam-busting bouncing bombs were child's play in comparison with today's unmanned surveillance drones.

Rawsthorn's title Hello World is irritatingly winsome. There is also the question of why the design of a book about design, with its dizzying vertical page numbers and inscrutable photography, is absolutely dire.

But this hardly detracts from the value and enjoyment of a sprightly survey that counteracts the narrowness with which so many people think about design.

Design, as Alice Rawsthorn points out, can mean a great many things. You can have designs on someone, as in making them an object of intrigue. You can design a corporate strategy, a gene, software, a lifestyle, a skyscraper, a menu, a razor. A designer can be a flouncy stylist of clothes or interiors, or someone in a laboratory coat, or, if you are a creationist, God.

So writing about design, if it is not to be impossibly broad, has to narrow the field somehow. Rawsthorn describes design as conceiving and implementing change in a particular way. The examples of "designer" that she mentions include such unorthodox examples as the 18th-century pirates who devised the skull-and-crossbones as a form of corporate identity, but are weighted towards more widely recognised examples such as the industrial designers Charles and Ray Eames, and Saul Bass, creator of memorable title sequences for Hitchcock and James Bond films.

She dwells on "Alpha companies" such as Wedgwood in the 18th century, the 19th-century chairmaker Thonet, the electronics company Braun and, above all, Apple. What these businesses have in common is their use of design to respond to technical innovation, and make it valuable, accessible and meaningful to their customers. Towards the end of the book she talks about people who address needs in developing countries, and are as much social entrepreneurs as conventional designers. These include Sanga Moses, who devised the means for Ugandan farmers to convert agricultural waste into fuel and fertiliser.

In general she favours the idea that good design is not about adding ornamental fripperies but about using ingenuity and technique to make people's lives better. With, hopefully, a bit of visual elegance thrown in. She has a beneficent view of design, and expects it to do good. She agonises over whether the devastatingly effective AK-47 gun can be considered "good design" and concludes that, as a killing machine, it cannot. (But then again, would a weapon used to defeat the bad guys, such as a Spitfire, qualify?)

This is a view that William Morris would recognise, or Walter Gropius, or the Design Council. It is basically right, but has limitations, a certain innocence, suggesting as it does a world of sweet reason which we don't inhabit. It deals lightly with moral complexity  should we love Apple, for example, for the lusciousness of its touchscreens, or fear it for the imperial hunger to command its market and own users' information? As Roland Barthes pointed out long ago, a designed object such as a car can have multiple and contradictory meanings. Rawsthorn nods to Barthes, but doesn't follow his leads.

Much of Hello World reads like a primer, trotting through the well-known themes and stories  the Bauhaus, the Crystal Palace, the London underground map. It does this with clarity and sanity, but can be dutiful and teacherly in tone. It is given to generalisations, an overuse of vague words such as "often", and predictable phrases: craftsmanship is exquisite, crowds flock, palaces are sumptuous. As a reader, you want more depth, more insight, more questioning, as she races from example to example.

It gets more interesting when the subjects are less predictable  there is an excursion into dog breeding, and a good passage on Aimee Mullins. She is a model, athlete and double amputee who has worked with designers to improve vastly what were once abysmal prostheses. She was also an inspiration to both Alexander McQueen and Matthew Barney, who designed fantastical new legs for her. Here Rawsthorn shows a more playful and eclectic, but still purposeful, spirit, which she also showed when she was director of the Design Museum.

There is more sense of direction when she gets on to the "other" (poorer) 90% on whom, she says, designers spend too little of their time. Addressing their needs tends to require more complex means  economic and political intelligence, for example  than the simple making of objects. She also sees this more strategic attitude, generally, as an increasingly important part of designers' work.

This is probably true, though it's a tad unfortunate that the "other 90%" only get about 10% of the book. You feel that there is the beginning of something interesting here, a polemic that might have powered the rest. But it only begins at the end.