XXXXXXX: Photo kisses

SO THAT'S what Cartier-Bresson meant by the decisive moment? No, no. Only kidding. Decisive, yes - but often in a small way. The pleasure of a kiss in a photograph comes from it ability to capture an emotion on the hoof - the snatched moment, the secret moment, an ecstatic moment, the superficial social peck without any moment at all. Sculptors and painters seldom achieve this casualness. Their kisses carry the full gob of emotional symbolism: The Kiss to represent all kisses, locked marble mouths summing up the whole of human desire. Photography doesn't pretend quite so much, because it's got context to deal with.

The best documentary photographs rely on the meeting of two narratives; the one behind the photograph and the one it triggers in our imagination - memory mostly, a transference of personal experience. So, when it comes to kissing, once we've got the context of the kiss, we can use our imagination to gauge its meaning. Bruce Davidson's American teenagers, entwined a back-seat embrace are, on one level, the perfect composition of youthful limbs and recklessness - teenage runaways from some Fifties road movie, with all the desperate romance that implies. But on another, most of us have done something similar, and what did it mean really? An old boyfriend, long forgotten? A first love, never bested? Lust and its unhappy consequences? A life before responsibility? Part of the strength of the picture comes from the knowledge of transience it carries with it. The same thing goes for Robert Doisneau's couple on the streets of Paris, probably the most famous photo-kiss of all time. From the twist of their bodies, we know that this was a momentary thing, an impulsive lovers' kiss, nothing historic. What is has is the fleeting possibility of pure romance.

When photographs record public events, kisses play a secondary role; exclamation marks in a historical narrative. Micha Bar- Am's photograph of the return of one of the Israeli hostages from Entebbe, being almost strangled in the hysterical assault of two women, grabbing, crying, disbelieving, kissing, is a great picture made more powerful by its historical context. But when context disappears, we have something like Man Ray's experimentalism. He made repeated attempts to pose the erotic: carefully placing his naked women, breast to breast, their lips within a Hay's code of meeting. But the resulting portraits are nowhere near so effective as another of his pictures, of Nusch Eluard and Sonia Mosse, fully dressed, one bent protectively over the other with a tenderness that, though still posed, seems more convincingly Sapphic.

Children kissing? Difficult. Sally Mann's own children - her habitual models - are used to her camera, but their innocent poses skirt the edge of eroticism. The dispute is over whether's it's implicit in her photographs or whether we impose it. Kiss Goodnight has a closeted sentimentality, reminiscent of Julia Margaret Cameron, beautiful but unsettling.

Elliott Erwitt, always on the lookout for life's photo-ops, took another all-comers' kiss (post card, poster, book-jacket, album cover) when he caught the laughing woman reflected in a wing mirror of an American car. This is the kind of photo-kiss that people love just because it defies reality, the kind of kiss we don't care to burden with cynicism - just absorb into our imagination and take emotional sustenance from it. These are dream kisses - the simple joys. Like another Erwitt picture of a frazzle-permed woman at a Birmingham dog show, wrapped closely in the arms of her Old English sheepdog, lips to snout in hairy ecstasy.