Art made with bodily fluids appears the essence of the weirdly and wonderfully new. Artist Rose-Lynn Fisher, for instance, has just made a series of landscape images using what she claims are 100 varieties of tears – revealing the difference between tears of sorrow and tears caused by chopping onions, and many other instances of weeping. Well, if you cry easily, you may as well get some art out it, I suppose.
This tearful art joins with outpourings of piss – most famously Andres Serrano's Piss Christ – and ejaculations of semen like Vito Acconci's Seedbed (who masturbated for eight hours) in the copious archive of body fluid art. Another artist who has used semen is Antony Gormley, while Matthew Barney extrudes all kinds of strange stuff in The Cremaster Trilogy, most of it probably synthetic but we can't be sure.
Yet the power of bodily fluids is no modern discovery. In ancient Maya art, we see depictions of bloodletting rituals that were central to the Maya religion. The art of the Aztecs includes impressive receptacles for the human blood that flowed from mass sacrifices. The very first painters mixed pigment with their own spit.
No art, however, is fixated quite so vividly on body fluids as that of Christian Europe. When artists today use body fluids to express inner states – which is what Rose-Lynn Fisher says she's doing: tears are a primal human act of communication, she insists – they are drawing on the blood, sweat, pus and tears that have been part of Christian art for centuries.
One of the great artistic relics of the middle ages was the Veil of Saint Veronica, a cloth said to be imprinted with the bloodied, weeping face of Christ at his death. It was widely depicted by artists who used it as physical evidence of what Christ looked like.
It has gone but that great medieval fake, the Turin Shroud, survives. Some of the marks on it may be bloodstains. Since carbon dating has placed it in the medieval period long after the death of Christ, the cunning forgers who created this bizarre artwork evidently used actual blood to add to its aura of reality.
In doing so they were only going an inch further than all the painters and sculptors who depicted Christ bleeding on the cross and the tears of Mary.
So Fisher and other artists who use bodily fluids are really part of a drive to make art physical and real that is deeply written into the art history of the Christian and post-Christian world.
Yet for all this passionate literalism, the most powerful tears in modern art are not "real" at all, nor do they look it. Picasso's Weeping Woman in Tate Modern, who cries an allegorical river of pain and redemption, proves you don"t need to actually cry, masturbate or bleed to be a great artist.