Gilbert and George have always maintained that they create sculptures. Their resolutely two-dimensional, barely-shadowed photographs plastered with unshaded colours, and the overall flatness of their work belies any possible traditional reading of sculpture. But the privileging of sculpture does suggest that the audience might notice how the Fundamental Pictures seeks the three-dimensional in seemingly undifferentiated forms: the dried crystals of urine, tears, semen, through to the foamy mass of sputum, to monumental turds. And in these miniscule (and not so miniscule) bodily scultpures, Gilbert and George have isolated their famous iconography, in particular the insouiciant juxtaposition of the religious and scatology (crosses, the crown of thorns in the dried semen).

The series, The Fundamental Pictures, is clearly an affront - to aesthetic sensibilities, to loving admirers who desperately want to enjoy Gilbert and George's work and not be nauseated by enormous turds, to an art world anxious that it won't be taken seriously, and to their critics, who, though superficially vindicated by the childishly provocative subject matter, can only writhe impotently as the work accrues value and significance. There are any number of psychoanalytic perspectives one can take on these pictures: the representation of the self through the microscopic prism in search of these fundamental stages of being, or the obsessively imagined value of excretia (shit literally turning into money). The Fundamental Pictures may also be read as part of Gilbert and George's bodily trajectory in their art, as the camera gets closer and closer to them, stripping them over time: from the suited young men in the British countryside to increasingly humiliating and revealing poses, and finally to their bodily fluids.

But the pieces also emerge from a specific moment in the history of bodily fluids, a transition from the 1980s, where fear of bodily fluids became a cultural hysteria (think of Rock Hudson's kiss) to the 1990s, where the hysteria had transitioned into a pathological universalism: now, with "universal precautions", all bodily fluids were potentially deadly. In medicine, the culture changed enormously. Students have always been exposed to training materials that come from a generation before, usually with a grainier hue and comic formality, but medical students in the 1990s could watch, with mouths open in horror, films of babies being delivered into ungloved hands.

The shock can only emerge from this disjuncture. Spit, defecation, urine, semen may have always been prohibited, taboo, revolting, and even recognised as a source of filth or germs, but now this was split off from social, epidemiological, or even biological assumptions (the specifications of the origins of the material): they were now intrinsically pathological (universally so). The Fundamental Pictures mirror the way in which bodily fluids ceased being personal, and instead became part of a universal pool of potentially transmissible pathology, full of weird shapes and familiar colours, nonspecific but the fundamental constituent of modern humanity.