[In the following review, Dyer judges Sontag as a master of the essay form, praising her work AIDS and Its Metaphors as well as the earlier essay Illness as Metaphor.]

Twelve years ago, when Susan Sontag became a cancer patient, she felt compelled to write a book about the disease, not a confessional account of the struggle against illness—“a narrative, it seemed to me, would be less useful than an idea”—but a broader genealogy and history of the metaphors associated with disease. Like a vaccine for which the world had been waiting, Illness as Metaphor achieved the immediate status of a classic, one of those books which seem always to have been around.

Disease, she argues in that book, should be seen as just that, otherwise the sick have to suffer not only physically but also from the weight of associations that a given sickness brings in its wake. At any time there tends to be one disease whose associations become so ideologically loaded as to make it seem a threat to society's economic or political health. In the era of early capitalist accumulation TB was seen as typifying the dangers of squandering, over-consumption—over-budgeting the body's resources. In the era of advanced capitalism, which requires speculation, credit and expenditure, cancer serves to express the dangers of repressing spontaneity, holding back and hoarding.

And now there is AIDS. With characteristic assurance Sontag notes [in AIDS and Its Metaphors] the way that this new disease has lent itself to military metaphors of invasion, how it quickly assumed the status of a plague against which the nation arms itself with a rhetoric of vague authoritarianism.

After two decades of steadily increasing sexual freedom—“sexual inflation”—we now find ourselves in the midst of a sexual depression. Even before AIDS a counter-current of moderation—diets, looking after yourself—was already challenging the sixties ideal of wild self-realisation; but with AIDS that self-restraining impulse had become an urgent imperative. So it has been in the arts, with a return to landscape and figure in painting, with jazz showing a retreat from free improvisation to the tighter structures of bebop. Neo-classicism, in a word.

So far so predictable, but Sontag extends her inquiry to consider the way that AIDS has taken its place among other possible catastrophes that are in the process of threatening the earth (the ozone layer, nuclear war). From there the argument soars as she wonders how “even an apocalypse can be made to seem part of the ordinary horizon of expectation”—but I want to stop there, just as we are getting to the best part.

It's a convention of fiction reviewing that you don't give the story away and this slim, beautifully produced book offers many of the pleasures of fiction (pleasures almost absent, incidentally, from Sontag's own laboriously modernist novels) as the pattern of ideas, clues and evidence emerges. It is in no way to diminish the content of AIDS and Its Metaphors—or Sontag's stature as a thinker—to emphasise how in her hands the essay becomes the most sensuous of literary forms. Sentences unfold with unruffled calm, bearing an imperceptibly increasing weight of meaning without ever becoming cumbersome. There is none of the back-wrenching strain of John Berger—though she has his urgency—none of the clause-twisting formulations of Raymond Williams—though her arguments have his force—no sense of sweating under the weight of accumulated erudition that we find in George Steiner—though she ranges as widely.

AIDS and Its Metaphors ranks alongside the best essays of any of these three: it is an important book about “the way we live now”—to lift the title of her own story about AIDS published in the New Yorker—and it is also the work of a stylist who, like Barthes, has mastered all the most difficult forms of writing: the colon, parentheses, italics, the semi-colon, ellipses …